diff --git a/blockchain/reactor.go b/blockchain/reactor.go
index 4543f22a..f7c7586e 100644
--- a/blockchain/reactor.go
+++ b/blockchain/reactor.go
@@ -221,7 +221,7 @@ FOR_LOOP:
 					// We need both to sync the first block.
 					break SYNC_LOOP
 				}
-				firstParts := first.MakePartSet(bcR.config.GetInt("block_part_size"))
+				firstParts := first.MakePartSet(bcR.config.GetInt("block_part_size")) // TODO: put part size in parts header?
 				firstPartsHeader := firstParts.Header()
 				// Finally, verify the first block using the second's commit
 				// NOTE: we can probably make this more efficient, but note that calling
@@ -236,6 +236,7 @@ FOR_LOOP:
 				} else {
 					bcR.pool.PopRequest()
 					// TODO: use ApplyBlock instead of Exec/Commit/SetAppHash/Save
+					// TODO: should we be firing events? need to fire NewBlock events manually ...
 					err := bcR.state.ExecBlock(bcR.evsw, bcR.proxyAppConn, first, firstPartsHeader)
 					if err != nil {
 						// TODO This is bad, are we zombie?
diff --git a/blockchain/store.go b/blockchain/store.go
index 565e131a..3b422642 100644
--- a/blockchain/store.go
+++ b/blockchain/store.go
@@ -163,6 +163,7 @@ func (bs *BlockStore) SaveBlock(block *types.Block, blockParts *types.PartSet, s
 	bs.db.Set(calcBlockCommitKey(height-1), blockCommitBytes)
 
 	// Save seen commit (seen +2/3 precommits for block)
+	// NOTE: we can delete this at a later height
 	seenCommitBytes := wire.BinaryBytes(seenCommit)
 	bs.db.Set(calcSeenCommitKey(height), seenCommitBytes)
 
diff --git a/consensus/byzantine_test.go b/consensus/byzantine_test.go
new file mode 100644
index 00000000..f049fa3e
--- /dev/null
+++ b/consensus/byzantine_test.go
@@ -0,0 +1,278 @@
+package consensus
+
+import (
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/tendermint/tendermint/config/tendermint_test"
+
+	. "github.com/tendermint/go-common"
+	cfg "github.com/tendermint/go-config"
+	"github.com/tendermint/go-crypto"
+	"github.com/tendermint/go-events"
+	"github.com/tendermint/go-p2p"
+	"github.com/tendermint/tendermint/types"
+)
+
+func init() {
+	config = tendermint_test.ResetConfig("consensus_byzantine_test")
+}
+
+//----------------------------------------------
+// byzantine failures
+
+// 4 validators. 1 is byzantine. The other three are partitioned into A (1 val) and B (2 vals).
+// byzantine validator sends conflicting proposals into A and B,
+// and prevotes/precommits on both of them.
+// B sees a commit, A doesn't.
+// Byzantine validator refuses to prevote.
+// Heal partition and ensure A sees the commit
+func TestByzantine(t *testing.T) {
+	resetConfigTimeouts()
+	N := 4
+	css := randConsensusNet(N)
+
+	switches := make([]*p2p.Switch, N)
+	for i := 0; i < N; i++ {
+		switches[i] = p2p.NewSwitch(cfg.NewMapConfig(nil))
+	}
+
+	reactors := make([]p2p.Reactor, N)
+	eventChans := make([]chan interface{}, N)
+	for i := 0; i < N; i++ {
+		if i == 0 {
+			css[i].privValidator = NewByzantinePrivValidator(css[i].privValidator.(*types.PrivValidator))
+			// make byzantine
+			css[i].decideProposal = func(j int) func(int, int) {
+				return func(height, round int) {
+					byzantineDecideProposalFunc(height, round, css[j], switches[j])
+				}
+			}(i)
+			css[i].doPrevote = func(height, round int) {}
+		}
+
+		eventSwitch := events.NewEventSwitch()
+		_, err := eventSwitch.Start()
+		if err != nil {
+			t.Fatalf("Failed to start switch: %v", err)
+		}
+		eventChans[i] = subscribeToEvent(eventSwitch, "tester", types.EventStringNewBlock(), 1)
+
+		conR := NewConsensusReactor(css[i], false)
+		conR.SetEventSwitch(eventSwitch)
+
+		var conRI p2p.Reactor
+		conRI = conR
+		if i == 0 {
+			conRI = NewByzantineReactor(conR)
+		}
+		reactors[i] = conRI
+	}
+
+	p2p.MakeConnectedSwitches(N, func(i int, s *p2p.Switch) *p2p.Switch {
+		// ignore new switch s, we already made ours
+		switches[i].AddReactor("CONSENSUS", reactors[i])
+		return switches[i]
+	}, func(sws []*p2p.Switch, i, j int) {
+		// the network starts partitioned with globally active adversary
+		if i != 0 {
+			return
+		}
+		p2p.Connect2Switches(sws, i, j)
+	})
+
+	// byz proposer sends one block to peers[0]
+	// and the other block to peers[1] and peers[2].
+	// note peers and switches order don't match.
+	peers := switches[0].Peers().List()
+	ind0 := getSwitchIndex(switches, peers[0])
+	ind1 := getSwitchIndex(switches, peers[1])
+	ind2 := getSwitchIndex(switches, peers[2])
+
+	// connect the 2 peers in the larger partition
+	p2p.Connect2Switches(switches, ind1, ind2)
+
+	// wait for someone in the big partition to make a block
+
+	select {
+	case <-eventChans[ind2]:
+	}
+
+	log.Notice("A block has been committed. Healing partition")
+
+	// connect the partitions
+	p2p.Connect2Switches(switches, ind0, ind1)
+	p2p.Connect2Switches(switches, ind0, ind2)
+
+	// wait till everyone makes the first new block
+	// (one of them already has)
+	wg := new(sync.WaitGroup)
+	wg.Add(2)
+	for i := 1; i < N-1; i++ {
+		go func(j int) {
+			<-eventChans[j]
+			wg.Done()
+		}(i)
+	}
+
+	done := make(chan struct{})
+	go func() {
+		wg.Wait()
+		close(done)
+	}()
+
+	tick := time.NewTicker(time.Second * 10)
+	select {
+	case <-done:
+	case <-tick.C:
+		for i, reactor := range reactors {
+			t.Log(Fmt("Consensus Reactor %v", i))
+			t.Log(Fmt("%v", reactor))
+		}
+		t.Fatalf("Timed out waiting for all validators to commit first block")
+	}
+}
+
+//-------------------------------
+// byzantine consensus functions
+
+func byzantineDecideProposalFunc(height, round int, cs *ConsensusState, sw *p2p.Switch) {
+	// byzantine user should create two proposals and try to split the vote.
+	// Avoid sending on internalMsgQueue and running consensus state.
+
+	// Create a new proposal block from state/txs from the mempool.
+	block1, blockParts1 := cs.createProposalBlock()
+	polRound, polBlockID := cs.Votes.POLInfo()
+	proposal1 := types.NewProposal(height, round, blockParts1.Header(), polRound, polBlockID)
+	cs.privValidator.SignProposal(cs.state.ChainID, proposal1) // byzantine doesnt err
+
+	// Create a new proposal block from state/txs from the mempool.
+	block2, blockParts2 := cs.createProposalBlock()
+	polRound, polBlockID = cs.Votes.POLInfo()
+	proposal2 := types.NewProposal(height, round, blockParts2.Header(), polRound, polBlockID)
+	cs.privValidator.SignProposal(cs.state.ChainID, proposal2) // byzantine doesnt err
+
+	block1Hash := block1.Hash()
+	block2Hash := block2.Hash()
+
+	// broadcast conflicting proposals/block parts to peers
+	peers := sw.Peers().List()
+	log.Notice("Byzantine: broadcasting conflicting proposals", "peers", len(peers))
+	for i, peer := range peers {
+		if i < len(peers)/2 {
+			go sendProposalAndParts(height, round, cs, peer, proposal1, block1Hash, blockParts1)
+		} else {
+			go sendProposalAndParts(height, round, cs, peer, proposal2, block2Hash, blockParts2)
+		}
+	}
+}
+
+func sendProposalAndParts(height, round int, cs *ConsensusState, peer *p2p.Peer, proposal *types.Proposal, blockHash []byte, parts *types.PartSet) {
+	// proposal
+	msg := &ProposalMessage{Proposal: proposal}
+	peer.Send(DataChannel, struct{ ConsensusMessage }{msg})
+
+	// parts
+	for i := 0; i < parts.Total(); i++ {
+		part := parts.GetPart(i)
+		msg := &BlockPartMessage{
+			Height: height, // This tells peer that this part applies to us.
+			Round:  round,  // This tells peer that this part applies to us.
+			Part:   part,
+		}
+		peer.Send(DataChannel, struct{ ConsensusMessage }{msg})
+	}
+
+	// votes
+	cs.mtx.Lock()
+	prevote, _ := cs.signVote(types.VoteTypePrevote, blockHash, parts.Header())
+	precommit, _ := cs.signVote(types.VoteTypePrecommit, blockHash, parts.Header())
+	cs.mtx.Unlock()
+
+	peer.Send(VoteChannel, struct{ ConsensusMessage }{&VoteMessage{prevote}})
+	peer.Send(VoteChannel, struct{ ConsensusMessage }{&VoteMessage{precommit}})
+}
+
+//----------------------------------------
+// byzantine consensus reactor
+
+type ByzantineReactor struct {
+	Service
+	reactor *ConsensusReactor
+}
+
+func NewByzantineReactor(conR *ConsensusReactor) *ByzantineReactor {
+	return &ByzantineReactor{
+		Service: conR,
+		reactor: conR,
+	}
+}
+
+func (br *ByzantineReactor) SetSwitch(s *p2p.Switch)               { br.reactor.SetSwitch(s) }
+func (br *ByzantineReactor) GetChannels() []*p2p.ChannelDescriptor { return br.reactor.GetChannels() }
+func (br *ByzantineReactor) AddPeer(peer *p2p.Peer) {
+	if !br.reactor.IsRunning() {
+		return
+	}
+
+	// Create peerState for peer
+	peerState := NewPeerState(peer)
+	peer.Data.Set(types.PeerStateKey, peerState)
+
+	// Send our state to peer.
+	// If we're fast_syncing, broadcast a RoundStepMessage later upon SwitchToConsensus().
+	if !br.reactor.fastSync {
+		br.reactor.sendNewRoundStepMessage(peer)
+	}
+}
+func (br *ByzantineReactor) RemovePeer(peer *p2p.Peer, reason interface{}) {
+	br.reactor.RemovePeer(peer, reason)
+}
+func (br *ByzantineReactor) Receive(chID byte, peer *p2p.Peer, msgBytes []byte) {
+	br.reactor.Receive(chID, peer, msgBytes)
+}
+
+//----------------------------------------
+// byzantine privValidator
+
+type ByzantinePrivValidator struct {
+	Address      []byte `json:"address"`
+	types.Signer `json:"-"`
+
+	mtx sync.Mutex
+}
+
+// Return a priv validator that will sign anything
+func NewByzantinePrivValidator(pv *types.PrivValidator) *ByzantinePrivValidator {
+	return &ByzantinePrivValidator{
+		Address: pv.Address,
+		Signer:  pv.Signer,
+	}
+}
+
+func (privVal *ByzantinePrivValidator) GetAddress() []byte {
+	return privVal.Address
+}
+
+func (privVal *ByzantinePrivValidator) SignVote(chainID string, vote *types.Vote) error {
+	privVal.mtx.Lock()
+	defer privVal.mtx.Unlock()
+
+	// Sign
+	vote.Signature = privVal.Sign(types.SignBytes(chainID, vote)).(crypto.SignatureEd25519)
+	return nil
+}
+
+func (privVal *ByzantinePrivValidator) SignProposal(chainID string, proposal *types.Proposal) error {
+	privVal.mtx.Lock()
+	defer privVal.mtx.Unlock()
+
+	// Sign
+	proposal.Signature = privVal.Sign(types.SignBytes(chainID, proposal)).(crypto.SignatureEd25519)
+	return nil
+}
+
+func (privVal *ByzantinePrivValidator) String() string {
+	return Fmt("PrivValidator{%X}", privVal.Address)
+}
diff --git a/consensus/common.go b/consensus/common.go
index 02b2c4a4..1f78c585 100644
--- a/consensus/common.go
+++ b/consensus/common.go
@@ -4,7 +4,7 @@ import (
 	"github.com/tendermint/tendermint/types"
 )
 
-// NOTE: this is blocking
+// NOTE: if chanCap=0, this blocks on the event being consumed
 func subscribeToEvent(evsw types.EventSwitch, receiver, eventID string, chanCap int) chan interface{} {
 	// listen for event
 	ch := make(chan interface{}, chanCap)
@@ -13,3 +13,14 @@ func subscribeToEvent(evsw types.EventSwitch, receiver, eventID string, chanCap
 	})
 	return ch
 }
+
+// NOTE: this blocks on receiving a response after the event is consumed
+func subscribeToEventRespond(evsw types.EventSwitch, receiver, eventID string) chan interface{} {
+	// listen for event
+	ch := make(chan interface{})
+	types.AddListenerForEvent(evsw, receiver, eventID, func(data types.TMEventData) {
+		ch <- data
+		<-ch
+	})
+	return ch
+}
diff --git a/consensus/common_test.go b/consensus/common_test.go
index 297b842e..7f15ab5f 100644
--- a/consensus/common_test.go
+++ b/consensus/common_test.go
@@ -3,6 +3,7 @@ package consensus
 import (
 	"bytes"
 	"fmt"
+	"io/ioutil"
 	"sort"
 	"sync"
 	"testing"
@@ -11,6 +12,7 @@ import (
 	. "github.com/tendermint/go-common"
 	cfg "github.com/tendermint/go-config"
 	dbm "github.com/tendermint/go-db"
+	"github.com/tendermint/go-p2p"
 	bc "github.com/tendermint/tendermint/blockchain"
 	"github.com/tendermint/tendermint/config/tendermint_test"
 	mempl "github.com/tendermint/tendermint/mempool"
@@ -33,6 +35,8 @@ type validatorStub struct {
 	*types.PrivValidator
 }
 
+var testMinPower = 10
+
 func NewValidatorStub(privValidator *types.PrivValidator, valIndex int) *validatorStub {
 	return &validatorStub{
 		Index:         valIndex,
@@ -266,6 +270,31 @@ func randConsensusNet(nValidators int) []*ConsensusState {
 	return css
 }
 
+// nPeers = nValidators + nNotValidator
+func randConsensusNetWithPeers(nValidators int, nPeers int) []*ConsensusState {
+	genDoc, privVals := randGenesisDoc(nValidators, false, int64(testMinPower))
+	css := make([]*ConsensusState, nPeers)
+	for i := 0; i < nPeers; i++ {
+		db := dbm.NewMemDB() // each state needs its own db
+		state := sm.MakeGenesisState(db, genDoc)
+		state.Save()
+		thisConfig := tendermint_test.ResetConfig(Fmt("consensus_reactor_test_%d", i))
+		EnsureDir(thisConfig.GetString("cs_wal_dir"), 0700) // dir for wal
+		var privVal *types.PrivValidator
+		if i < nValidators {
+			privVal = privVals[i]
+		} else {
+			privVal = types.GenPrivValidator()
+			_, tempFilePath := Tempfile("priv_validator_")
+			privVal.SetFile(tempFilePath)
+		}
+
+		dir, _ := ioutil.TempDir("/tmp", "persistent-dummy")
+		css[i] = newConsensusStateWithConfig(thisConfig, state, privVal, dummy.NewPersistentDummyApplication(dir))
+	}
+	return css
+}
+
 func subscribeToVoter(cs *ConsensusState, addr []byte) chan interface{} {
 	voteCh0 := subscribeToEvent(cs.evsw, "tester", types.EventStringVote(), 1)
 	voteCh := make(chan interface{})
@@ -325,3 +354,16 @@ func startTestRound(cs *ConsensusState, height, round int) {
 	cs.enterNewRound(height, round)
 	cs.startRoutines(0)
 }
+
+//--------------------------------
+// reactor stuff
+
+func getSwitchIndex(switches []*p2p.Switch, peer *p2p.Peer) int {
+	for i, s := range switches {
+		if bytes.Equal(peer.NodeInfo.PubKey.Address(), s.NodeInfo().PubKey.Address()) {
+			return i
+		}
+	}
+	panic("didnt find peer in switches")
+	return -1
+}
diff --git a/consensus/reactor.go b/consensus/reactor.go
index 60d5a8f5..6190fc52 100644
--- a/consensus/reactor.go
+++ b/consensus/reactor.go
@@ -287,11 +287,6 @@ func (conR *ConsensusReactor) Receive(chID byte, src *p2p.Peer, msgBytes []byte)
 	}
 }
 
-// Sets our private validator account for signing votes.
-func (conR *ConsensusReactor) SetPrivValidator(priv PrivValidator) {
-	conR.conS.SetPrivValidator(priv)
-}
-
 // implements events.Eventable
 func (conR *ConsensusReactor) SetEventSwitch(evsw types.EventSwitch) {
 	conR.evsw = evsw
@@ -954,7 +949,7 @@ func (ps *PeerState) SetHasVote(vote *types.Vote) {
 
 func (ps *PeerState) setHasVote(height int, round int, type_ byte, index int) {
 	log := log.New("peer", ps.Peer, "peerRound", ps.Round, "height", height, "round", round)
-	log.Info("setHasVote(LastCommit)", "lastCommit", ps.LastCommit, "index", index)
+	log.Debug("setHasVote(LastCommit)", "lastCommit", ps.LastCommit, "index", index)
 
 	// NOTE: some may be nil BitArrays -> no side effects.
 	ps.getVoteBitArray(height, round, type_).SetIndex(index, true)
diff --git a/consensus/reactor_test.go b/consensus/reactor_test.go
index 6b76d2aa..504bd97f 100644
--- a/consensus/reactor_test.go
+++ b/consensus/reactor_test.go
@@ -1,20 +1,18 @@
 package consensus
 
 import (
-	"bytes"
+	"fmt"
 	"sync"
 	"testing"
 	"time"
 
 	"github.com/tendermint/tendermint/config/tendermint_test"
 
-	. "github.com/tendermint/go-common"
-	cfg "github.com/tendermint/go-config"
-	"github.com/tendermint/go-crypto"
 	"github.com/tendermint/go-events"
 	"github.com/tendermint/go-logger"
 	"github.com/tendermint/go-p2p"
 	"github.com/tendermint/tendermint/types"
+	"github.com/tendermint/tmsp/example/dummy"
 )
 
 func init() {
@@ -22,7 +20,7 @@ func init() {
 }
 
 func resetConfigTimeouts() {
-	logger.SetLogLevel("notice")
+	logger.SetLogLevel("info")
 	//config.Set("log_level", "notice")
 	config.Set("timeout_propose", 2000)
 	//	config.Set("timeout_propose_delta", 500)
@@ -30,9 +28,13 @@ func resetConfigTimeouts() {
 	//	config.Set("timeout_prevote_delta", 500)
 	//	config.Set("timeout_precommit", 1000)
 	//	config.Set("timeout_precommit_delta", 500)
-	//	config.Set("timeout_commit", 1000)
+	config.Set("timeout_commit", 1000)
 }
 
+//----------------------------------------------
+// in-process testnets
+
+// Ensure a testnet makes blocks
 func TestReactor(t *testing.T) {
 	resetConfigTimeouts()
 	N := 4
@@ -41,7 +43,6 @@ func TestReactor(t *testing.T) {
 	eventChans := make([]chan interface{}, N)
 	for i := 0; i < N; i++ {
 		reactors[i] = NewConsensusReactor(css[i], false)
-		reactors[i].SetPrivValidator(css[i].privValidator)
 
 		eventSwitch := events.NewEventSwitch()
 		_, err := eventSwitch.Start()
@@ -52,19 +53,120 @@ func TestReactor(t *testing.T) {
 		reactors[i].SetEventSwitch(eventSwitch)
 		eventChans[i] = subscribeToEvent(eventSwitch, "tester", types.EventStringNewBlock(), 1)
 	}
+	// make connected switches and start all reactors
 	p2p.MakeConnectedSwitches(N, func(i int, s *p2p.Switch) *p2p.Switch {
 		s.AddReactor("CONSENSUS", reactors[i])
 		return s
 	}, p2p.Connect2Switches)
 
 	// wait till everyone makes the first new block
+	timeoutWaitGroup(t, N, func(wg *sync.WaitGroup, j int) {
+		<-eventChans[j]
+		wg.Done()
+	})
+}
+
+//-------------------------------------------------------------
+// ensure we can make blocks despite cycling a validator set
+
+func TestValidatorSetChanges(t *testing.T) {
+	resetConfigTimeouts()
+	nPeers := 8
+	nVals := 4
+	css := randConsensusNetWithPeers(nVals, nPeers)
+	reactors := make([]*ConsensusReactor, nPeers)
+	eventChans := make([]chan interface{}, nPeers)
+	for i := 0; i < nPeers; i++ {
+		reactors[i] = NewConsensusReactor(css[i], false)
+
+		eventSwitch := events.NewEventSwitch()
+		_, err := eventSwitch.Start()
+		if err != nil {
+			t.Fatalf("Failed to start switch: %v", err)
+		}
+
+		reactors[i].SetEventSwitch(eventSwitch)
+		eventChans[i] = subscribeToEventRespond(eventSwitch, "tester", types.EventStringNewBlock())
+	}
+	p2p.MakeConnectedSwitches(nPeers, func(i int, s *p2p.Switch) *p2p.Switch {
+		s.AddReactor("CONSENSUS", reactors[i])
+		return s
+	}, p2p.Connect2Switches)
+
+	// map of active validators
+	activeVals := make(map[string]struct{})
+	for i := 0; i < nVals; i++ {
+		activeVals[string(css[i].privValidator.GetAddress())] = struct{}{}
+	}
+
+	// wait till everyone makes block 1
+	timeoutWaitGroup(t, nPeers, func(wg *sync.WaitGroup, j int) {
+		<-eventChans[j]
+		eventChans[j] <- struct{}{}
+		wg.Done()
+	})
+
+	newValidatorPubKey := css[nVals].privValidator.(*types.PrivValidator).PubKey
+	newValidatorTx := dummy.MakeValSetChangeTx(newValidatorPubKey.Bytes(), uint64(testMinPower))
+
+	// wait till everyone makes block 2
+	// ensure the commit includes all validators
+	// send newValTx to change vals in block 3
+	waitForAndValidateBlock(t, nPeers, activeVals, eventChans, css, newValidatorTx)
+
+	// wait till everyone makes block 3.
+	// it includes the commit for block 2, which is by the original validator set
+	waitForAndValidateBlock(t, nPeers, activeVals, eventChans, css)
+
+	// wait till everyone makes block 4.
+	// it includes the commit for block 3, which is by the original validator set
+	waitForAndValidateBlock(t, nPeers, activeVals, eventChans, css)
+
+	// the commits for block 4 should be with the updated validator set
+	activeVals[string(newValidatorPubKey.Address())] = struct{}{}
+
+	// wait till everyone makes block 5
+	// it includes the commit for block 4, which should have the updated validator set
+	waitForAndValidateBlock(t, nPeers, activeVals, eventChans, css)
+
+	// TODO: test more changes!
+}
+
+func waitForAndValidateBlock(t *testing.T, n int, activeVals map[string]struct{}, eventChans []chan interface{}, css []*ConsensusState, txs ...[]byte) {
+	timeoutWaitGroup(t, n, func(wg *sync.WaitGroup, j int) {
+		newBlock := <-eventChans[j]
+		err := validateBlock(newBlock.(types.EventDataNewBlock).Block, activeVals)
+		if err != nil {
+			t.Fatal(err)
+		}
+		for _, tx := range txs {
+			css[j].mempool.CheckTx(tx, nil)
+		}
+
+		eventChans[j] <- struct{}{}
+		wg.Done()
+	})
+}
+
+// expects high synchrony!
+func validateBlock(block *types.Block, activeVals map[string]struct{}) error {
+	if block.LastCommit.Size() != len(activeVals) {
+		return fmt.Errorf("Commit size doesn't match number of active validators. Got %d, expected %d", block.LastCommit.Size(), len(activeVals))
+	}
+
+	for _, vote := range block.LastCommit.Precommits {
+		if _, ok := activeVals[string(vote.ValidatorAddress)]; !ok {
+			return fmt.Errorf("Found vote for unactive validator %X", vote.ValidatorAddress)
+		}
+	}
+	return nil
+}
+
+func timeoutWaitGroup(t *testing.T, n int, f func(*sync.WaitGroup, int)) {
 	wg := new(sync.WaitGroup)
-	wg.Add(N)
-	for i := 0; i < N; i++ {
-		go func(j int) {
-			<-eventChans[j]
-			wg.Done()
-		}(i)
+	wg.Add(n)
+	for i := 0; i < n; i++ {
+		go f(wg, i)
 	}
 
 	// Make wait into a channel
@@ -78,274 +180,6 @@ func TestReactor(t *testing.T) {
 	select {
 	case <-done:
 	case <-tick.C:
-		t.Fatalf("Timed out waiting for all validators to commit first block")
+		t.Fatalf("Timed out waiting for all validators to commit a block")
 	}
 }
-
-// 4 validators. 1 is byzantine. The other three are partitioned into A (1 val) and B (2 vals).
-// byzantine validator sends conflicting proposals into A and B,
-// and prevotes/precommits on both of them.
-// B sees a commit, A doesn't.
-// Byzantine validator refuses to prevote.
-// Heal partition and ensure A sees the commit
-func TestByzantine(t *testing.T) {
-	resetConfigTimeouts()
-	N := 4
-	css := randConsensusNet(N)
-
-	switches := make([]*p2p.Switch, N)
-	for i := 0; i < N; i++ {
-		switches[i] = p2p.NewSwitch(cfg.NewMapConfig(nil))
-	}
-
-	reactors := make([]p2p.Reactor, N)
-	eventChans := make([]chan interface{}, N)
-	for i := 0; i < N; i++ {
-		var privVal PrivValidator
-		privVal = css[i].privValidator
-		if i == 0 {
-			privVal = NewByzantinePrivValidator(privVal.(*types.PrivValidator))
-			// make byzantine
-			css[i].decideProposal = func(j int) func(int, int) {
-				return func(height, round int) {
-					byzantineDecideProposalFunc(height, round, css[j], switches[j])
-				}
-			}(i)
-			css[i].doPrevote = func(height, round int) {}
-		}
-
-		eventSwitch := events.NewEventSwitch()
-		_, err := eventSwitch.Start()
-		if err != nil {
-			t.Fatalf("Failed to start switch: %v", err)
-		}
-		eventChans[i] = subscribeToEvent(eventSwitch, "tester", types.EventStringNewBlock(), 1)
-
-		conR := NewConsensusReactor(css[i], false)
-		conR.SetPrivValidator(privVal)
-		conR.SetEventSwitch(eventSwitch)
-
-		var conRI p2p.Reactor
-		conRI = conR
-		if i == 0 {
-			conRI = NewByzantineReactor(conR)
-		}
-		reactors[i] = conRI
-	}
-
-	p2p.MakeConnectedSwitches(N, func(i int, s *p2p.Switch) *p2p.Switch {
-		// ignore new switch s, we already made ours
-		switches[i].AddReactor("CONSENSUS", reactors[i])
-		return switches[i]
-	}, func(sws []*p2p.Switch, i, j int) {
-		// the network starts partitioned with globally active adversary
-		if i != 0 {
-			return
-		}
-		p2p.Connect2Switches(sws, i, j)
-	})
-
-	// byz proposer sends one block to peers[0]
-	// and the other block to peers[1] and peers[2].
-	// note peers and switches order don't match.
-	peers := switches[0].Peers().List()
-	ind0 := getSwitchIndex(switches, peers[0])
-	ind1 := getSwitchIndex(switches, peers[1])
-	ind2 := getSwitchIndex(switches, peers[2])
-
-	// connect the 2 peers in the larger partition
-	p2p.Connect2Switches(switches, ind1, ind2)
-
-	// wait for someone in the big partition to make a block
-
-	select {
-	case <-eventChans[ind2]:
-	}
-
-	log.Notice("A block has been committed. Healing partition")
-
-	// connect the partitions
-	p2p.Connect2Switches(switches, ind0, ind1)
-	p2p.Connect2Switches(switches, ind0, ind2)
-
-	// wait till everyone makes the first new block
-	// (one of them already has)
-	wg := new(sync.WaitGroup)
-	wg.Add(2)
-	for i := 1; i < N-1; i++ {
-		go func(j int) {
-			<-eventChans[j]
-			wg.Done()
-		}(i)
-	}
-
-	done := make(chan struct{})
-	go func() {
-		wg.Wait()
-		close(done)
-	}()
-
-	tick := time.NewTicker(time.Second * 10)
-	select {
-	case <-done:
-	case <-tick.C:
-		for i, reactor := range reactors {
-			t.Log(Fmt("Consensus Reactor %v", i))
-			t.Log(Fmt("%v", reactor))
-		}
-		t.Fatalf("Timed out waiting for all validators to commit first block")
-	}
-}
-
-func getSwitchIndex(switches []*p2p.Switch, peer *p2p.Peer) int {
-	for i, s := range switches {
-		if bytes.Equal(peer.NodeInfo.PubKey.Address(), s.NodeInfo().PubKey.Address()) {
-			return i
-		}
-	}
-	panic("didnt find peer in switches")
-	return -1
-}
-
-//-------------------------------
-// byzantine consensus functions
-
-func byzantineDecideProposalFunc(height, round int, cs *ConsensusState, sw *p2p.Switch) {
-	// byzantine user should create two proposals and try to split the vote.
-	// Avoid sending on internalMsgQueue and running consensus state.
-
-	// Create a new proposal block from state/txs from the mempool.
-	block1, blockParts1 := cs.createProposalBlock()
-	polRound, polBlockID := cs.Votes.POLInfo()
-	proposal1 := types.NewProposal(height, round, blockParts1.Header(), polRound, polBlockID)
-	cs.privValidator.SignProposal(cs.state.ChainID, proposal1) // byzantine doesnt err
-
-	// Create a new proposal block from state/txs from the mempool.
-	block2, blockParts2 := cs.createProposalBlock()
-	polRound, polBlockID = cs.Votes.POLInfo()
-	proposal2 := types.NewProposal(height, round, blockParts2.Header(), polRound, polBlockID)
-	cs.privValidator.SignProposal(cs.state.ChainID, proposal2) // byzantine doesnt err
-
-	block1Hash := block1.Hash()
-	block2Hash := block2.Hash()
-
-	// broadcast conflicting proposals/block parts to peers
-	peers := sw.Peers().List()
-	log.Notice("Byzantine: broadcasting conflicting proposals", "peers", len(peers))
-	for i, peer := range peers {
-		if i < len(peers)/2 {
-			go sendProposalAndParts(height, round, cs, peer, proposal1, block1Hash, blockParts1)
-		} else {
-			go sendProposalAndParts(height, round, cs, peer, proposal2, block2Hash, blockParts2)
-		}
-	}
-}
-
-func sendProposalAndParts(height, round int, cs *ConsensusState, peer *p2p.Peer, proposal *types.Proposal, blockHash []byte, parts *types.PartSet) {
-	// proposal
-	msg := &ProposalMessage{Proposal: proposal}
-	peer.Send(DataChannel, struct{ ConsensusMessage }{msg})
-
-	// parts
-	for i := 0; i < parts.Total(); i++ {
-		part := parts.GetPart(i)
-		msg := &BlockPartMessage{
-			Height: height, // This tells peer that this part applies to us.
-			Round:  round,  // This tells peer that this part applies to us.
-			Part:   part,
-		}
-		peer.Send(DataChannel, struct{ ConsensusMessage }{msg})
-	}
-
-	// votes
-	cs.mtx.Lock()
-	prevote, _ := cs.signVote(types.VoteTypePrevote, blockHash, parts.Header())
-	precommit, _ := cs.signVote(types.VoteTypePrecommit, blockHash, parts.Header())
-	cs.mtx.Unlock()
-
-	peer.Send(VoteChannel, struct{ ConsensusMessage }{&VoteMessage{prevote}})
-	peer.Send(VoteChannel, struct{ ConsensusMessage }{&VoteMessage{precommit}})
-}
-
-//----------------------------------------
-// byzantine consensus reactor
-
-type ByzantineReactor struct {
-	Service
-	reactor *ConsensusReactor
-}
-
-func NewByzantineReactor(conR *ConsensusReactor) *ByzantineReactor {
-	return &ByzantineReactor{
-		Service: conR,
-		reactor: conR,
-	}
-}
-
-func (br *ByzantineReactor) SetSwitch(s *p2p.Switch)               { br.reactor.SetSwitch(s) }
-func (br *ByzantineReactor) GetChannels() []*p2p.ChannelDescriptor { return br.reactor.GetChannels() }
-func (br *ByzantineReactor) AddPeer(peer *p2p.Peer) {
-	if !br.reactor.IsRunning() {
-		return
-	}
-
-	// Create peerState for peer
-	peerState := NewPeerState(peer)
-	peer.Data.Set(types.PeerStateKey, peerState)
-
-	// Send our state to peer.
-	// If we're fast_syncing, broadcast a RoundStepMessage later upon SwitchToConsensus().
-	if !br.reactor.fastSync {
-		br.reactor.sendNewRoundStepMessage(peer)
-	}
-}
-func (br *ByzantineReactor) RemovePeer(peer *p2p.Peer, reason interface{}) {
-	br.reactor.RemovePeer(peer, reason)
-}
-func (br *ByzantineReactor) Receive(chID byte, peer *p2p.Peer, msgBytes []byte) {
-	br.reactor.Receive(chID, peer, msgBytes)
-}
-
-//----------------------------------------
-// byzantine privValidator
-
-type ByzantinePrivValidator struct {
-	Address      []byte `json:"address"`
-	types.Signer `json:"-"`
-
-	mtx sync.Mutex
-}
-
-// Return a priv validator that will sign anything
-func NewByzantinePrivValidator(pv *types.PrivValidator) *ByzantinePrivValidator {
-	return &ByzantinePrivValidator{
-		Address: pv.Address,
-		Signer:  pv.Signer,
-	}
-}
-
-func (privVal *ByzantinePrivValidator) GetAddress() []byte {
-	return privVal.Address
-}
-
-func (privVal *ByzantinePrivValidator) SignVote(chainID string, vote *types.Vote) error {
-	privVal.mtx.Lock()
-	defer privVal.mtx.Unlock()
-
-	// Sign
-	vote.Signature = privVal.Sign(types.SignBytes(chainID, vote)).(crypto.SignatureEd25519)
-	return nil
-}
-
-func (privVal *ByzantinePrivValidator) SignProposal(chainID string, proposal *types.Proposal) error {
-	privVal.mtx.Lock()
-	defer privVal.mtx.Unlock()
-
-	// Sign
-	proposal.Signature = privVal.Sign(types.SignBytes(chainID, proposal)).(crypto.SignatureEd25519)
-	return nil
-}
-
-func (privVal *ByzantinePrivValidator) String() string {
-	return Fmt("PrivValidator{%X}", privVal.Address)
-}
diff --git a/consensus/state.go b/consensus/state.go
index 85d4d167..bef286e1 100644
--- a/consensus/state.go
+++ b/consensus/state.go
@@ -221,11 +221,12 @@ type PrivValidator interface {
 type ConsensusState struct {
 	BaseService
 
-	config        cfg.Config
-	proxyAppConn  proxy.AppConnConsensus
-	blockStore    *bc.BlockStore
-	mempool       *mempl.Mempool
-	privValidator PrivValidator
+	config       cfg.Config
+	proxyAppConn proxy.AppConnConsensus
+	blockStore   *bc.BlockStore
+	mempool      *mempl.Mempool
+
+	privValidator PrivValidator // for signing votes
 
 	mtx sync.Mutex
 	RoundState
@@ -313,6 +314,7 @@ func (cs *ConsensusState) GetValidators() (int, []*types.Validator) {
 	return cs.state.LastBlockHeight, cs.state.Validators.Copy().Validators
 }
 
+// Sets our private validator account for signing votes.
 func (cs *ConsensusState) SetPrivValidator(priv PrivValidator) {
 	cs.mtx.Lock()
 	defer cs.mtx.Unlock()
@@ -1253,6 +1255,8 @@ func (cs *ConsensusState) finalizeCommit(height int) {
 
 	// Save to blockStore.
 	if cs.blockStore.Height() < block.Height {
+		// NOTE: the seenCommit is local justification to commit this block,
+		// but may differ from the LastCommit included in the next block
 		precommits := cs.Votes.Precommits(cs.CommitRound)
 		seenCommit := precommits.MakeCommit()
 		cs.blockStore.SaveBlock(block, blockParts, seenCommit)
@@ -1498,7 +1502,6 @@ func (cs *ConsensusState) addVote(vote *types.Vote, peerKey string) (added bool,
 }
 
 func (cs *ConsensusState) signVote(type_ byte, hash []byte, header types.PartSetHeader) (*types.Vote, error) {
-	// TODO: store our index in the cs so we don't have to do this every time
 	addr := cs.privValidator.GetAddress()
 	valIndex, _ := cs.Validators.GetByAddress(addr)
 	vote := &types.Vote{
@@ -1515,6 +1518,7 @@ func (cs *ConsensusState) signVote(type_ byte, hash []byte, header types.PartSet
 
 // sign the vote and publish on internalMsgQueue
 func (cs *ConsensusState) signAddVote(type_ byte, hash []byte, header types.PartSetHeader) *types.Vote {
+	// if we don't have a key or we're not in the validator set, do nothing
 	if cs.privValidator == nil || !cs.Validators.HasAddress(cs.privValidator.GetAddress()) {
 		return nil
 	}
diff --git a/glide.lock b/glide.lock
index cbaa5f88..68296b90 100644
--- a/glide.lock
+++ b/glide.lock
@@ -1,8 +1,8 @@
 hash: 20cb38481a78b73ba3a42af08e34cd825ddb7c826833d67cc61e45c1b3a4c484
-updated: 2016-11-16T16:25:10.693961906-05:00
+updated: 2016-11-23T18:28:52.925584919-05:00
 imports:
 - name: github.com/btcsuite/btcd
-  version: b134beb3b7809de6370a93cc5f6a684d6942e2e8
+  version: afec1bd1245a4a19e6dfe1306974b733e7cbb9b8
   subpackages:
   - btcec
 - name: github.com/btcsuite/fastsha256
@@ -18,7 +18,7 @@ imports:
   subpackages:
   - proto
 - name: github.com/golang/protobuf
-  version: 224aaba33b1ac32a92a165f27489409fb8133d08
+  version: 8ee79997227bf9b34611aee7946ae64735e6fd93
   subpackages:
   - proto
 - name: github.com/golang/snappy
@@ -28,7 +28,7 @@ imports:
 - name: github.com/mattn/go-colorable
   version: d228849504861217f796da67fae4f6e347643f15
 - name: github.com/mattn/go-isatty
-  version: 66b8e73f3f5cda9f96b69efd03dd3d7fc4a5cdb8
+  version: 30a891c33c7cde7b02a981314b4228ec99380cca
 - name: github.com/spf13/pflag
   version: 5ccb023bc27df288a957c5e994cd44fd19619465
 - name: github.com/syndtr/goleveldb
@@ -58,7 +58,7 @@ imports:
 - name: github.com/tendermint/go-clist
   version: 3baa390bbaf7634251c42ad69a8682e7e3990552
 - name: github.com/tendermint/go-common
-  version: fa3daa7abc253264c916c12fecce3effa01a1287
+  version: 6b4160f2a57487f277c42bf06fd280195dfdb278
   subpackages:
   - test
 - name: github.com/tendermint/go-config
@@ -76,9 +76,9 @@ imports:
 - name: github.com/tendermint/go-logger
   version: cefb3a45c0bf3c493a04e9bcd9b1540528be59f2
 - name: github.com/tendermint/go-merkle
-  version: 05042c6ab9cad51d12e4cecf717ae68e3b1409a8
+  version: bfc4afe28c7a50045d4d1eb043e67460f8a51a4f
 - name: github.com/tendermint/go-p2p
-  version: 62b37014a89b5eddff74844846979d30911cffda
+  version: f173a17ed3e9b341d480b36e5041819c8a5b8350
   subpackages:
   - upnp
 - name: github.com/tendermint/go-rpc
@@ -94,7 +94,7 @@ imports:
   subpackages:
   - term
 - name: github.com/tendermint/tmsp
-  version: 0bdb3b887e70b1ef16d32eece0248ec071fd8490
+  version: 3742e35e6db5dcd7596aac9f661b46f5699ebec8
   subpackages:
   - client
   - example/counter
@@ -103,7 +103,7 @@ imports:
   - server
   - types
 - name: golang.org/x/crypto
-  version: 9477e0b78b9ac3d0b03822fd95422e2fe07627cd
+  version: ede567c8e044a5913dad1d1af3696d9da953104c
   subpackages:
   - curve25519
   - nacl/box
@@ -124,11 +124,11 @@ imports:
   - lex/httplex
   - trace
 - name: golang.org/x/sys
-  version: b699b7032584f0953262cb2788a0ca19bb494703
+  version: 30237cf4eefd639b184d1f2cb77a581ea0be8947
   subpackages:
   - unix
 - name: google.golang.org/grpc
-  version: 941cc894cea3c87a12943fd12b594964541b6d28
+  version: eca2ad68af4d7bf894ada6bd263133f069a441d5
   subpackages:
   - codes
   - credentials
diff --git a/node/node.go b/node/node.go
index f4a04d82..dcde7fac 100644
--- a/node/node.go
+++ b/node/node.go
@@ -101,10 +101,10 @@ func NewNode(config cfg.Config, privValidator *types.PrivValidator, clientCreato
 
 	// Make ConsensusReactor
 	consensusState := consensus.NewConsensusState(config, state.Copy(), proxyApp.Consensus(), blockStore, mempool)
-	consensusReactor := consensus.NewConsensusReactor(consensusState, fastSync)
 	if privValidator != nil {
-		consensusReactor.SetPrivValidator(privValidator)
+		consensusState.SetPrivValidator(privValidator)
 	}
+	consensusReactor := consensus.NewConsensusReactor(consensusState, fastSync)
 
 	// Make p2p network switch
 	sw := p2p.NewSwitch(config.GetConfig("p2p"))
diff --git a/rpc/test/client_test.go b/rpc/test/client_test.go
index ddc84ef0..728e87bd 100644
--- a/rpc/test/client_test.go
+++ b/rpc/test/client_test.go
@@ -5,13 +5,14 @@ import (
 	crand "crypto/rand"
 	"fmt"
 	"math/rand"
-	"strings"
 	"testing"
 	"time"
 
 	. "github.com/tendermint/go-common"
+	"github.com/tendermint/go-wire"
 	ctypes "github.com/tendermint/tendermint/rpc/core/types"
 	"github.com/tendermint/tendermint/types"
+	"github.com/tendermint/tmsp/example/dummy"
 	tmsp "github.com/tendermint/tmsp/types"
 )
 
@@ -156,9 +157,14 @@ func testTMSPQuery(t *testing.T, statusI interface{}, value []byte) {
 	if query.Result.IsErr() {
 		panic(Fmt("Query returned an err: %v", query))
 	}
+
+	qResult := new(dummy.QueryResult)
+	if err := wire.ReadJSONBytes(query.Result.Data, qResult); err != nil {
+		t.Fatal(err)
+	}
 	// XXX: specific to value returned by the dummy
-	if !strings.Contains(string(query.Result.Data), "exists=true") {
-		panic(Fmt("Query error. Expected to find 'exists=true'. Got: %s", query.Result.Data))
+	if qResult.Exists != true {
+		panic(Fmt("Query error. Expected to find 'exists=true'. Got: %v", qResult))
 	}
 }
 
diff --git a/state/execution.go b/state/execution.go
index c52be41d..07466c77 100644
--- a/state/execution.go
+++ b/state/execution.go
@@ -8,6 +8,7 @@ import (
 
 	. "github.com/tendermint/go-common"
 	cfg "github.com/tendermint/go-config"
+	"github.com/tendermint/go-crypto"
 	"github.com/tendermint/tendermint/proxy"
 	"github.com/tendermint/tendermint/types"
 	tmsp "github.com/tendermint/tmsp/types"
@@ -21,26 +22,33 @@ import (
 func (s *State) ExecBlock(eventCache types.Fireable, proxyAppConn proxy.AppConnConsensus, block *types.Block, blockPartsHeader types.PartSetHeader) error {
 
 	// Validate the block.
-	err := s.validateBlock(block)
-	if err != nil {
+	if err := s.validateBlock(block); err != nil {
 		return ErrInvalidBlock(err)
 	}
 
-	// Update the validator set
+	// compute bitarray of validators that signed
+	signed := commitBitArrayFromBlock(block)
+	_ = signed // TODO send on begin block
+
+	// copy the valset
 	valSet := s.Validators.Copy()
-	// Update valSet with signatures from block.
-	updateValidatorsWithBlock(s.LastValidators, valSet, block)
-	// TODO: Update the validator set (e.g. block.Data.ValidatorUpdates?)
 	nextValSet := valSet.Copy()
 
 	// Execute the block txs
-	err = s.execBlockOnProxyApp(eventCache, proxyAppConn, block)
+	changedValidators, err := execBlockOnProxyApp(eventCache, proxyAppConn, block)
 	if err != nil {
 		// There was some error in proxyApp
 		// TODO Report error and wait for proxyApp to be available.
 		return ErrProxyAppConn(err)
 	}
 
+	// update the validator set
+	err = updateValidators(nextValSet, changedValidators)
+	if err != nil {
+		log.Warn("Error changing validator set", "error", err)
+		// TODO: err or carry on?
+	}
+
 	// All good!
 	// Update validator accums and set state variables
 	nextValSet.IncrementAccum(1)
@@ -54,8 +62,9 @@ func (s *State) ExecBlock(eventCache types.Fireable, proxyAppConn proxy.AppConnC
 }
 
 // Executes block's transactions on proxyAppConn.
+// Returns a list of updates to the validator set
 // TODO: Generate a bitmap or otherwise store tx validity in state.
-func (s *State) execBlockOnProxyApp(eventCache types.Fireable, proxyAppConn proxy.AppConnConsensus, block *types.Block) error {
+func execBlockOnProxyApp(eventCache types.Fireable, proxyAppConn proxy.AppConnConsensus, block *types.Block) ([]*tmsp.Validator, error) {
 
 	var validTxs, invalidTxs = 0, 0
 
@@ -94,7 +103,7 @@ func (s *State) execBlockOnProxyApp(eventCache types.Fireable, proxyAppConn prox
 	err := proxyAppConn.BeginBlockSync(block.Hash(), types.TM2PB.Header(block.Header))
 	if err != nil {
 		log.Warn("Error in proxyAppConn.BeginBlock", "error", err)
-		return err
+		return nil, err
 	}
 
 	fail.Fail() // XXX
@@ -104,7 +113,7 @@ func (s *State) execBlockOnProxyApp(eventCache types.Fireable, proxyAppConn prox
 		fail.FailRand(len(block.Txs)) // XXX
 		proxyAppConn.AppendTxAsync(tx)
 		if err := proxyAppConn.Error(); err != nil {
-			return err
+			return nil, err
 		}
 	}
 
@@ -114,44 +123,69 @@ func (s *State) execBlockOnProxyApp(eventCache types.Fireable, proxyAppConn prox
 	changedValidators, err := proxyAppConn.EndBlockSync(uint64(block.Height))
 	if err != nil {
 		log.Warn("Error in proxyAppConn.EndBlock", "error", err)
-		return err
+		return nil, err
 	}
 
 	fail.Fail() // XXX
 
-	// TODO: Do something with changedValidators
-	log.Debug("TODO: Do something with changedValidators", "changedValidators", changedValidators)
+	log.Info("Executed block", "height", block.Height, "valid txs", validTxs, "invalid txs", invalidTxs)
+	if len(changedValidators) > 0 {
+		log.Info("Update to validator set", "updates", tmsp.ValidatorsString(changedValidators))
+	}
+	return changedValidators, nil
+}
 
-	log.Info(Fmt("ExecBlock got %v valid txs and %v invalid txs", validTxs, invalidTxs))
+func updateValidators(validators *types.ValidatorSet, changedValidators []*tmsp.Validator) error {
+	// TODO: prevent change of 1/3+ at once
+
+	for _, v := range changedValidators {
+		pubkey, err := crypto.PubKeyFromBytes(v.PubKey) // NOTE: expects go-wire encoded pubkey
+		if err != nil {
+			return err
+		}
+
+		address := pubkey.Address()
+		power := int64(v.Power)
+		// mind the overflow from uint64
+		if power < 0 {
+			return errors.New(Fmt("Power (%d) overflows int64", v.Power))
+		}
+
+		_, val := validators.GetByAddress(address)
+		if val == nil {
+			// add val
+			added := validators.Add(types.NewValidator(pubkey, power))
+			if !added {
+				return errors.New(Fmt("Failed to add new validator %X with voting power %d", address, power))
+			}
+		} else if v.Power == 0 {
+			// remove val
+			_, removed := validators.Remove(address)
+			if !removed {
+				return errors.New(Fmt("Failed to remove validator %X)"))
+			}
+		} else {
+			// update val
+			val.VotingPower = power
+			updated := validators.Update(val)
+			if !updated {
+				return errors.New(Fmt("Failed to update validator %X with voting power %d", address, power))
+			}
+		}
+	}
 	return nil
 }
 
-// Updates the LastCommitHeight of the validators in valSet, in place.
-// Assumes that lastValSet matches the valset of block.LastCommit
-// CONTRACT: lastValSet is not mutated.
-func updateValidatorsWithBlock(lastValSet *types.ValidatorSet, valSet *types.ValidatorSet, block *types.Block) {
-
+// return a bit array of validators that signed the last commit
+// NOTE: assumes commits have already been authenticated
+func commitBitArrayFromBlock(block *types.Block) *BitArray {
+	signed := NewBitArray(len(block.LastCommit.Precommits))
 	for i, precommit := range block.LastCommit.Precommits {
-		if precommit == nil {
-			continue
-		}
-		_, val := lastValSet.GetByIndex(i)
-		if val == nil {
-			PanicCrisis(Fmt("Failed to fetch validator at index %v", i))
-		}
-		if _, val_ := valSet.GetByAddress(val.Address); val_ != nil {
-			val_.LastCommitHeight = block.Height - 1
-			updated := valSet.Update(val_)
-			if !updated {
-				PanicCrisis("Failed to update validator LastCommitHeight")
-			}
-		} else {
-			// XXX This is not an error if validator was removed.
-			// But, we don't mutate validators yet so go ahead and panic.
-			PanicCrisis("Could not find validator")
+		if precommit != nil {
+			signed.SetIndex(i, true) // val_.LastCommitHeight = block.Height - 1
 		}
 	}
-
+	return signed
 }
 
 //-----------------------------------------------------
@@ -259,6 +293,7 @@ func (m mockMempool) Update(height int, txs []types.Tx) {}
 type BlockStore interface {
 	Height() int
 	LoadBlock(height int) *types.Block
+	LoadBlockMeta(height int) *types.BlockMeta
 }
 
 type Handshaker struct {
@@ -273,8 +308,7 @@ func NewHandshaker(config cfg.Config, state *State, store BlockStore) *Handshake
 	return &Handshaker{config, state, store, 0}
 }
 
-// TODO: retry the handshake once if it fails the first time
-// ... let Info take an argument determining its behaviour
+// TODO: retry the handshake/replay if it fails ?
 func (h *Handshaker) Handshake(proxyApp proxy.AppConns) error {
 	// handshake is done via info request on the query conn
 	res, tmspInfo, blockInfo, configInfo := proxyApp.Query().InfoSync()
@@ -287,10 +321,9 @@ func (h *Handshaker) Handshake(proxyApp proxy.AppConns) error {
 		return nil
 	}
 
-	log.Notice("TMSP Handshake", "height", blockInfo.BlockHeight, "block_hash", blockInfo.BlockHash, "app_hash", blockInfo.AppHash)
+	log.Notice("TMSP Handshake", "height", blockInfo.BlockHeight, "app_hash", blockInfo.AppHash)
 
-	blockHeight := int(blockInfo.BlockHeight) // safe, should be an int32
-	blockHash := blockInfo.BlockHash
+	blockHeight := int(blockInfo.BlockHeight) // XXX: beware overflow
 	appHash := blockInfo.AppHash
 
 	if tmspInfo != nil {
@@ -298,40 +331,13 @@ func (h *Handshaker) Handshake(proxyApp proxy.AppConns) error {
 		_ = tmspInfo
 	}
 
-	// last block (nil if we starting from 0)
-	var header *types.Header
-	var partsHeader types.PartSetHeader
-
-	// replay all blocks after blockHeight
-	// if blockHeight == 0, we will replay everything
-	if blockHeight != 0 {
-		block := h.store.LoadBlock(blockHeight)
-		if block == nil {
-			return ErrUnknownBlock{blockHeight}
-		}
-
-		// check block hash
-		if !bytes.Equal(block.Hash(), blockHash) {
-			return ErrBlockHashMismatch{block.Hash(), blockHash, blockHeight}
-		}
-
-		// NOTE: app hash should be in the next block ...
-		// check app hash
-		/*if !bytes.Equal(block.Header.AppHash, appHash) {
-			return fmt.Errorf("Handshake error. App hash at height %d does not match. Got %X, expected %X", blockHeight, appHash, block.Header.AppHash)
-		}*/
-
-		header = block.Header
-		partsHeader = block.MakePartSet(h.config.GetInt("block_part_size")).Header()
-	}
-
 	if configInfo != nil {
 		// TODO: set config info
 		_ = configInfo
 	}
 
 	// replay blocks up to the latest in the blockstore
-	err := h.ReplayBlocks(appHash, header, partsHeader, proxyApp.Consensus())
+	err := h.ReplayBlocks(appHash, blockHeight, proxyApp.Consensus())
 	if err != nil {
 		return errors.New(Fmt("Error on replay: %v", err))
 	}
@@ -342,97 +348,72 @@ func (h *Handshaker) Handshake(proxyApp proxy.AppConns) error {
 }
 
 // Replay all blocks after blockHeight and ensure the result matches the current state.
-func (h *Handshaker) ReplayBlocks(appHash []byte, header *types.Header, partsHeader types.PartSetHeader,
-	appConnConsensus proxy.AppConnConsensus) error {
+func (h *Handshaker) ReplayBlocks(appHash []byte, appBlockHeight int, appConnConsensus proxy.AppConnConsensus) error {
 
-	// NOTE/TODO: tendermint may crash after the app commits
-	// but before it can save the new state root.
-	// it should save all eg. valset changes before calling Commit.
-	// then, if tm state is behind app state, the only thing missing can be app hash
-
-	// get a fresh state and reset to the apps latest
-	stateCopy := h.state.Copy()
-
-	// TODO: put validators in iavl tree so we can set the state with an older validator set
-	lastVals, nextVals := stateCopy.GetValidators()
-	if header == nil {
-		stateCopy.LastBlockHeight = 0
-		stateCopy.LastBlockID = types.BlockID{}
-		// stateCopy.LastBlockTime = ... doesnt matter
-		stateCopy.Validators = nextVals
-		stateCopy.LastValidators = lastVals
-	} else {
-		stateCopy.SetBlockAndValidators(header, partsHeader, lastVals, nextVals)
-	}
-	stateCopy.Stale = false
-	stateCopy.AppHash = appHash
-
-	appBlockHeight := stateCopy.LastBlockHeight
-	coreBlockHeight := h.store.Height()
-	if coreBlockHeight < appBlockHeight {
+	storeBlockHeight := h.store.Height()
+	if storeBlockHeight < appBlockHeight {
 		// if the app is ahead, there's nothing we can do
-		return ErrAppBlockHeightTooHigh{coreBlockHeight, appBlockHeight}
+		return ErrAppBlockHeightTooHigh{storeBlockHeight, appBlockHeight}
 
-	} else if coreBlockHeight == appBlockHeight {
+	} else if storeBlockHeight == appBlockHeight {
 		// if we crashed between Commit and SaveState,
-		// the state's app hash is stale.
+		// the state's app hash is stale
 		// otherwise we're synced
-		if h.state.Stale {
-			h.state.Stale = false
+		if h.state.AppHashIsStale {
+			h.state.AppHashIsStale = false
 			h.state.AppHash = appHash
 		}
-		return checkState(h.state, stateCopy)
+		return nil
 
 	} else if h.state.LastBlockHeight == appBlockHeight {
-		// core is ahead of app but core's state height is at apps height
+		// store is ahead of app but core's state height is at apps height
 		// this happens if we crashed after saving the block,
 		// but before committing it. We should be 1 ahead
-		if coreBlockHeight != appBlockHeight+1 {
-			PanicSanity(Fmt("core.state.height == app.height but core.height (%d) > app.height+1 (%d)", coreBlockHeight, appBlockHeight+1))
+		if storeBlockHeight != appBlockHeight+1 {
+			PanicSanity(Fmt("core.state.height == app.height but store.height (%d) > app.height+1 (%d)", storeBlockHeight, appBlockHeight+1))
 		}
 
 		// check that the blocks last apphash is the states apphash
-		block := h.store.LoadBlock(coreBlockHeight)
+		block := h.store.LoadBlock(storeBlockHeight)
 		if !bytes.Equal(block.Header.AppHash, appHash) {
-			return ErrLastStateMismatch{coreBlockHeight, block.Header.AppHash, appHash}
+			return ErrLastStateMismatch{storeBlockHeight, block.Header.AppHash, appHash}
 		}
 
-		// replay the block against the actual tendermint state (not the copy)
-		return h.loadApplyBlock(coreBlockHeight, h.state, appConnConsensus)
+		blockMeta := h.store.LoadBlockMeta(storeBlockHeight)
+
+		h.nBlocks += 1
+		var eventCache types.Fireable // nil
+
+		// replay the block against the actual tendermint state
+		return h.state.ApplyBlock(eventCache, appConnConsensus, block, blockMeta.PartsHeader, mockMempool{})
 
 	} else {
 		// either we're caught up or there's blocks to replay
 		// replay all blocks starting with appBlockHeight+1
-		for i := appBlockHeight + 1; i <= coreBlockHeight; i++ {
-			h.loadApplyBlock(i, stateCopy, appConnConsensus)
+		var eventCache types.Fireable // nil
+		var appHash []byte
+		for i := appBlockHeight + 1; i <= storeBlockHeight; i++ {
+			h.nBlocks += 1
+			block := h.store.LoadBlock(i)
+			_, err := execBlockOnProxyApp(eventCache, appConnConsensus, block)
+			if err != nil {
+				log.Warn("Error executing block on proxy app", "height", i, "err", err)
+				return err
+			}
+			// Commit block, get hash back
+			res := appConnConsensus.CommitSync()
+			if res.IsErr() {
+				log.Warn("Error in proxyAppConn.CommitSync", "error", res)
+				return res
+			}
+			if res.Log != "" {
+				log.Info("Commit.Log: " + res.Log)
+			}
+			appHash = res.Data
 		}
-		return checkState(h.state, stateCopy)
-	}
-}
-
-func checkState(s, stateCopy *State) error {
-	// The computed state and the previously set state should be identical
-	if !s.Equals(stateCopy) {
-		return ErrStateMismatch{stateCopy, s}
-	}
-	return nil
-}
-
-func (h *Handshaker) loadApplyBlock(blockIndex int, state *State, appConnConsensus proxy.AppConnConsensus) error {
-	h.nBlocks += 1
-	block := h.store.LoadBlock(blockIndex)
-	panicOnNilBlock(blockIndex, h.store.Height(), block) // XXX
-	var eventCache types.Fireable                        // nil
-	return state.ApplyBlock(eventCache, appConnConsensus, block, block.MakePartSet(h.config.GetInt("block_part_size")).Header(), mockMempool{})
-}
-
-func panicOnNilBlock(height, bsHeight int, block *types.Block) {
-	if block == nil {
-		// Sanity?
-		PanicCrisis(Fmt(`
-block is nil for height <= blockStore.Height() (%d <= %d).
-Block: %v,
-`, height, bsHeight, block))
-
+		if !bytes.Equal(h.state.AppHash, appHash) {
+			return errors.New(Fmt("Tendermint state.AppHash does not match AppHash after replay", "expected", h.state.AppHash, "got", appHash))
+		}
+		return nil
 	}
 }
diff --git a/state/execution_test.go b/state/execution_test.go
index dabcada6..e0527a42 100644
--- a/state/execution_test.go
+++ b/state/execution_test.go
@@ -8,6 +8,7 @@ import (
 
 	"github.com/tendermint/tendermint/config/tendermint_test"
 	//	. "github.com/tendermint/go-common"
+	cfg "github.com/tendermint/go-config"
 	"github.com/tendermint/go-crypto"
 	dbm "github.com/tendermint/go-db"
 	"github.com/tendermint/tendermint/proxy"
@@ -23,10 +24,16 @@ var (
 	testPartSize = 65536
 )
 
+//---------------------------------------
+// Test block execution
+
 func TestExecBlock(t *testing.T) {
 	// TODO
 }
 
+//---------------------------------------
+// Test handshake/replay
+
 // Sync from scratch
 func TestHandshakeReplayAll(t *testing.T) {
 	testHandshakeReplay(t, 0)
@@ -51,7 +58,7 @@ func TestHandshakeReplayNone(t *testing.T) {
 func testHandshakeReplay(t *testing.T, n int) {
 	config := tendermint_test.ResetConfig("proxy_test_")
 
-	state, store := stateAndStore()
+	state, store := stateAndStore(config)
 	clientCreator := proxy.NewLocalClientCreator(dummy.NewPersistentDummyApplication(path.Join(config.GetString("db_dir"), "1")))
 	clientCreator2 := proxy.NewLocalClientCreator(dummy.NewPersistentDummyApplication(path.Join(config.GetString("db_dir"), "2")))
 	proxyApp := proxy.NewAppConns(config, clientCreator, NewHandshaker(config, state, store))
@@ -69,7 +76,7 @@ func testHandshakeReplay(t *testing.T, n int) {
 		if _, err := proxyApp.Start(); err != nil {
 			t.Fatalf("Error starting proxy app connections: %v", err)
 		}
-		state2, _ := stateAndStore()
+		state2, _ := stateAndStore(config)
 		for i := 0; i < n; i++ {
 			block := chain[i]
 			err := state2.ApplyBlock(nil, proxyApp.Consensus(), block, block.MakePartSet(testPartSize).Header(), mempool)
@@ -105,6 +112,7 @@ func testHandshakeReplay(t *testing.T, n int) {
 }
 
 //--------------------------
+// utils for making blocks
 
 // make some bogus txs
 func txsFunc(blockNum int) (txs []types.Tx) {
@@ -167,7 +175,7 @@ func makeBlockchain(t *testing.T, proxyApp proxy.AppConns, state *State) (blockc
 }
 
 // fresh state and mock store
-func stateAndStore() (*State, *mockBlockStore) {
+func stateAndStore(config cfg.Config) (*State, *mockBlockStore) {
 	stateDB := dbm.NewMemDB()
 	return MakeGenesisState(stateDB, &types.GenesisDoc{
 		ChainID: chainID,
@@ -175,19 +183,28 @@ func stateAndStore() (*State, *mockBlockStore) {
 			types.GenesisValidator{privKey.PubKey(), 10000, "test"},
 		},
 		AppHash: nil,
-	}), NewMockBlockStore(nil)
+	}), NewMockBlockStore(config, nil)
 }
 
 //----------------------------------
 // mock block store
 
 type mockBlockStore struct {
-	chain []*types.Block
+	config cfg.Config
+	chain  []*types.Block
 }
 
-func NewMockBlockStore(chain []*types.Block) *mockBlockStore {
-	return &mockBlockStore{chain}
+func NewMockBlockStore(config cfg.Config, chain []*types.Block) *mockBlockStore {
+	return &mockBlockStore{config, chain}
 }
 
 func (bs *mockBlockStore) Height() int                       { return len(bs.chain) }
 func (bs *mockBlockStore) LoadBlock(height int) *types.Block { return bs.chain[height-1] }
+func (bs *mockBlockStore) LoadBlockMeta(height int) *types.BlockMeta {
+	block := bs.chain[height-1]
+	return &types.BlockMeta{
+		Hash:        block.Hash(),
+		Header:      block.Header,
+		PartsHeader: block.MakePartSet(bs.config.GetInt("block_part_size")).Header(),
+	}
+}
diff --git a/state/state.go b/state/state.go
index 4a54dfe6..f8b5dfc2 100644
--- a/state/state.go
+++ b/state/state.go
@@ -34,12 +34,12 @@ type State struct {
 	LastBlockID     types.BlockID
 	LastBlockTime   time.Time
 	Validators      *types.ValidatorSet
-	LastValidators  *types.ValidatorSet
+	LastValidators  *types.ValidatorSet // block.LastCommit validated against this
 
 	// AppHash is updated after Commit;
 	// it's stale after ExecBlock and before Commit
-	Stale   bool
-	AppHash []byte
+	AppHashIsStale bool
+	AppHash        []byte
 }
 
 func LoadState(db dbm.DB) *State {
@@ -60,6 +60,9 @@ func LoadState(db dbm.DB) *State {
 }
 
 func (s *State) Copy() *State {
+	if s.AppHashIsStale {
+		PanicSanity(Fmt("App hash is stale: %v", s))
+	}
 	return &State{
 		db:              s.db,
 		GenesisDoc:      s.GenesisDoc,
@@ -69,7 +72,7 @@ func (s *State) Copy() *State {
 		LastBlockTime:   s.LastBlockTime,
 		Validators:      s.Validators.Copy(),
 		LastValidators:  s.LastValidators.Copy(),
-		Stale:           s.Stale, // XXX: but really state shouldnt be copied while its stale
+		AppHashIsStale:  false,
 		AppHash:         s.AppHash,
 	}
 }
@@ -94,7 +97,7 @@ func (s *State) Bytes() []byte {
 }
 
 // Mutate state variables to match block and validators
-// Since we don't have the new AppHash yet, we set s.Stale=true
+// Since we don't have the new AppHash yet, we set s.AppHashIsStale=true
 func (s *State) SetBlockAndValidators(header *types.Header, blockPartsHeader types.PartSetHeader, prevValSet, nextValSet *types.ValidatorSet) {
 	s.LastBlockHeight = header.Height
 	s.LastBlockID = types.BlockID{header.Hash(), blockPartsHeader}
@@ -102,7 +105,7 @@ func (s *State) SetBlockAndValidators(header *types.Header, blockPartsHeader typ
 	s.Validators = nextValSet
 	s.LastValidators = prevValSet
 
-	s.Stale = true
+	s.AppHashIsStale = true
 }
 
 func (s *State) GetValidators() (*types.ValidatorSet, *types.ValidatorSet) {
diff --git a/test/app/dummy_test.sh b/test/app/dummy_test.sh
index bb17c6c3..c0907bd4 100644
--- a/test/app/dummy_test.sh
+++ b/test/app/dummy_test.sh
@@ -26,7 +26,7 @@ echo ""
 RESPONSE=`tmsp-cli query $KEY`
 
 set +e
-A=`echo $RESPONSE | grep exists=true`
+A=`echo $RESPONSE | grep '"exists":true'`
 if [[ $? != 0 ]]; then
 	echo "Failed to find 'exists=true' for $KEY. Response:"
 	echo "$RESPONSE"
@@ -37,7 +37,7 @@ set -e
 # we should not be able to look up the value
 RESPONSE=`tmsp-cli query $VALUE`
 set +e
-A=`echo $RESPONSE | grep exists=true`
+A=`echo $RESPONSE | grep '"exists":true'`
 if [[ $? == 0 ]]; then
 	echo "Found 'exists=true' for $VALUE when we should not have. Response:"
 	echo "$RESPONSE"
@@ -54,7 +54,7 @@ RESPONSE=`curl -s 127.0.0.1:46657/tmsp_query?query=\"$(toHex $KEY)\"`
 RESPONSE=`echo $RESPONSE | jq .result[1].result.Data | xxd -r -p`
 
 set +e
-A=`echo $RESPONSE | grep exists=true`
+A=`echo $RESPONSE | grep '"exists":true'`
 if [[ $? != 0 ]]; then
 	echo "Failed to find 'exists=true' for $KEY. Response:"
 	echo "$RESPONSE"
@@ -66,7 +66,7 @@ set -e
 RESPONSE=`curl -s 127.0.0.1:46657/tmsp_query?query=\"$(toHex $VALUE)\"`
 RESPONSE=`echo $RESPONSE | jq .result[1].result.Data | xxd -r -p`
 set +e
-A=`echo $RESPONSE | grep exists=true`
+A=`echo $RESPONSE | grep '"exists":true'`
 if [[ $? == 0 ]]; then
 	echo "Found 'exists=true' for $VALUE when we should not have. Response:"
 	echo "$RESPONSE"
diff --git a/types/block.go b/types/block.go
index 80a59f8a..e9574adf 100644
--- a/types/block.go
+++ b/types/block.go
@@ -21,6 +21,7 @@ type Block struct {
 	LastCommit *Commit `json:"last_commit"`
 }
 
+// TODO: version
 func MakeBlock(height int, chainID string, txs []Tx, commit *Commit,
 	prevBlockID BlockID, valHash, appHash []byte, partSize int) (*Block, *PartSet) {
 	block := &Block{
@@ -150,14 +151,15 @@ func (b *Block) StringShort() string {
 
 type Header struct {
 	ChainID        string    `json:"chain_id"`
+	Version        string    `json:"version"` // TODO:
 	Height         int       `json:"height"`
 	Time           time.Time `json:"time"`
-	NumTxs         int       `json:"num_txs"`
+	NumTxs         int       `json:"num_txs"` // XXX: Can we get rid of this?
 	LastBlockID    BlockID   `json:"last_block_id"`
-	LastCommitHash []byte    `json:"last_commit_hash"`
-	DataHash       []byte    `json:"data_hash"`
-	ValidatorsHash []byte    `json:"validators_hash"`
-	AppHash        []byte    `json:"app_hash"` // state merkle root of txs from the previous block
+	LastCommitHash []byte    `json:"last_commit_hash"` // commit from validators from the last block
+	DataHash       []byte    `json:"data_hash"`        // transactions
+	ValidatorsHash []byte    `json:"validators_hash"`  // validators for the current block
+	AppHash        []byte    `json:"app_hash"`         // state after txs from the previous block
 }
 
 // NOTE: hash is nil if required fields are missing.
@@ -291,6 +293,8 @@ func (commit *Commit) ValidateBasic() error {
 		return errors.New("No precommits in commit")
 	}
 	height, round := commit.Height(), commit.Round()
+
+	// validate the precommits
 	for _, precommit := range commit.Precommits {
 		// It's OK for precommits to be missing.
 		if precommit == nil {
diff --git a/types/protobuf.go b/types/protobuf.go
index a7a95d12..e1f03353 100644
--- a/types/protobuf.go
+++ b/types/protobuf.go
@@ -12,7 +12,7 @@ type tm2pb struct{}
 func (tm2pb) Header(header *Header) *types.Header {
 	return &types.Header{
 		ChainId:        header.ChainID,
-		Height:         int32(header.Height),
+		Height:         uint64(header.Height),
 		Time:           uint64(header.Time.Unix()),
 		NumTxs:         uint64(header.NumTxs),
 		LastBlockId:    TM2PB.BlockID(header.LastBlockID),
diff --git a/types/validator.go b/types/validator.go
index 2e45ebba..479824e6 100644
--- a/types/validator.go
+++ b/types/validator.go
@@ -12,14 +12,21 @@ import (
 
 // Volatile state for each Validator
 // TODO: make non-volatile identity
-// 	- Remove LastCommitHeight, send bitarray of vals that signed in BeginBlock
 // 	- Remove Accum - it can be computed, and now valset becomes identifying
 type Validator struct {
-	Address          []byte        `json:"address"`
-	PubKey           crypto.PubKey `json:"pub_key"`
-	LastCommitHeight int           `json:"last_commit_height"`
-	VotingPower      int64         `json:"voting_power"`
-	Accum            int64         `json:"accum"`
+	Address     []byte        `json:"address"`
+	PubKey      crypto.PubKey `json:"pub_key"`
+	VotingPower int64         `json:"voting_power"`
+	Accum       int64         `json:"accum"`
+}
+
+func NewValidator(pubKey crypto.PubKey, votingPower int64) *Validator {
+	return &Validator{
+		Address:     pubKey.Address(),
+		PubKey:      pubKey,
+		VotingPower: votingPower,
+		Accum:       0,
+	}
 }
 
 // Creates a new copy of the validator so we can mutate accum.
@@ -57,7 +64,6 @@ func (v *Validator) String() string {
 	return fmt.Sprintf("Validator{%X %v %v VP:%v A:%v}",
 		v.Address,
 		v.PubKey,
-		v.LastCommitHeight,
 		v.VotingPower,
 		v.Accum)
 }
@@ -96,12 +102,6 @@ func RandValidator(randPower bool, minPower int64) (*Validator, *PrivValidator)
 	if randPower {
 		votePower += int64(RandUint32())
 	}
-	val := &Validator{
-		Address:          privVal.Address,
-		PubKey:           privVal.PubKey,
-		LastCommitHeight: 0,
-		VotingPower:      votePower,
-		Accum:            0,
-	}
+	val := NewValidator(privVal.PubKey, votePower)
 	return val, privVal
 }
diff --git a/types/validator_set_test.go b/types/validator_set_test.go
index a94a4ebb..9107e77e 100644
--- a/types/validator_set_test.go
+++ b/types/validator_set_test.go
@@ -16,12 +16,9 @@ func randPubKey() crypto.PubKeyEd25519 {
 }
 
 func randValidator_() *Validator {
-	return &Validator{
-		Address:     RandBytes(20),
-		PubKey:      randPubKey(),
-		VotingPower: RandInt64(),
-		Accum:       RandInt64(),
-	}
+	val := NewValidator(randPubKey(), RandInt64())
+	val.Accum = RandInt64()
+	return val
 }
 
 func randValidatorSet(numValidators int) *ValidatorSet {
@@ -147,10 +144,7 @@ func BenchmarkValidatorSetCopy(b *testing.B) {
 	for i := 0; i < 1000; i++ {
 		privKey := crypto.GenPrivKeyEd25519()
 		pubKey := privKey.PubKey().(crypto.PubKeyEd25519)
-		val := &Validator{
-			Address: pubKey.Address(),
-			PubKey:  pubKey,
-		}
+		val := NewValidator(pubKey, 0)
 		if !vset.Add(val) {
 			panic("Failed to add validator")
 		}