diff --git a/Cargo.toml b/Cargo.toml
index ba6f4ab..d213493 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -30,6 +30,7 @@ merkle = { git = "https://github.com/afck/merkle.rs", branch = "public-proof", f
 pairing = { version = "0.14.2", features = ["u128-support"] }
 protobuf = { version = "2.0.0", optional = true }
 rand = "0.4.2"
+rand_derive = "0.3.1"
 reed-solomon-erasure = "3.1.0"
 ring = "^0.12"
 serde = "1.0.55"
diff --git a/examples/simulation.rs b/examples/simulation.rs
index 87850cf..5fb8efc 100644
--- a/examples/simulation.rs
+++ b/examples/simulation.rs
@@ -6,6 +6,8 @@ extern crate hbbft;
 extern crate itertools;
 extern crate pairing;
 extern crate rand;
+#[macro_use]
+extern crate rand_derive;
 extern crate serde;
 #[macro_use(Deserialize, Serialize)]
 extern crate serde_derive;
@@ -62,7 +64,7 @@ struct Args {
 }
 
 /// A node identifier. In the simulation, nodes are simply numbered.
-#[derive(Serialize, Deserialize, Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Clone, Copy)]
+#[derive(Serialize, Deserialize, Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Clone, Copy, Rand)]
 pub struct NodeUid(pub usize);
 
 /// A transaction.
diff --git a/src/agreement/bin_values.rs b/src/agreement/bin_values.rs
index ac2b931..12081bc 100644
--- a/src/agreement/bin_values.rs
+++ b/src/agreement/bin_values.rs
@@ -3,7 +3,7 @@ use std::mem::replace;
 
 /// A lattice-valued description of the state of `bin_values`, essentially the same as the set of
 /// subsets of `bool`.
-#[derive(Serialize, Deserialize, Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
+#[derive(Serialize, Deserialize, Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Rand)]
 pub enum BinValues {
     None,
     False,
@@ -63,7 +63,7 @@ impl BinValues {
         }
     }
 
-    pub fn contains(&self, b: bool) -> bool {
+    pub fn contains(self, b: bool) -> bool {
         match self {
             BinValues::None => false,
             BinValues::Both => true,
@@ -73,7 +73,7 @@ impl BinValues {
         }
     }
 
-    pub fn is_subset(&self, other: BinValues) -> bool {
+    pub fn is_subset(self, other: BinValues) -> bool {
         match self {
             BinValues::None => true,
             BinValues::False if other == BinValues::False || other == BinValues::Both => true,
@@ -83,7 +83,7 @@ impl BinValues {
         }
     }
 
-    pub fn definite(&self) -> Option<bool> {
+    pub fn definite(self) -> Option<bool> {
         match self {
             BinValues::False => Some(false),
             BinValues::True => Some(true),
diff --git a/src/agreement/mod.rs b/src/agreement/mod.rs
index 8dfdb0c..1c7b65b 100644
--- a/src/agreement/mod.rs
+++ b/src/agreement/mod.rs
@@ -65,6 +65,7 @@
 
 pub mod bin_values;
 
+use rand;
 use std::collections::{BTreeMap, BTreeSet, VecDeque};
 use std::fmt::Debug;
 use std::mem::replace;
@@ -122,12 +123,32 @@ impl AgreementContent {
 }
 
 /// Messages sent during the binary Byzantine agreement stage.
-#[derive(Serialize, Deserialize, Clone, Debug, PartialEq)]
+#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Rand)]
 pub struct AgreementMessage {
     pub epoch: u32,
     pub content: AgreementContent,
 }
 
+// NOTE: Extending rand_derive to correctly generate random values from boxes would make this
+// implementation obsolete; however at the time of this writing, `rand::Rand` is already deprecated
+// with no replacement in sight.
+impl rand::Rand for AgreementContent {
+    fn rand<R: rand::Rng>(rng: &mut R) -> Self {
+        let message_type = *rng
+            .choose(&["bval", "aux", "conf", "term", "coin"])
+            .unwrap();
+
+        match message_type {
+            "bval" => AgreementContent::BVal(rand::random()),
+            "aux" => AgreementContent::Aux(rand::random()),
+            "conf" => AgreementContent::Conf(rand::random()),
+            "term" => AgreementContent::Term(rand::random()),
+            "coin" => AgreementContent::Coin(Box::new(rand::random())),
+            _ => unreachable!(),
+        }
+    }
+}
+
 /// Possible values of the common coin schedule defining the method to derive the common coin in a
 /// given epoch: as a constant value or a distributed computation.
 enum CoinSchedule {
diff --git a/src/broadcast.rs b/src/broadcast.rs
index 3a2704b..1aacb40 100644
--- a/src/broadcast.rs
+++ b/src/broadcast.rs
@@ -40,6 +40,102 @@
 //! node will eventually be able to decode (i.e. receive at least _2 f + 1_ `Echo` messages).
 //! * So a node with _2 f + 1_ `Ready`s and _2 f + 1_ `Echos` will decode and _output_ the value,
 //! knowing that every other correct node will eventually do the same.
+//!
+//! ## Example usage
+//!
+//! ```rust
+//!# extern crate clear_on_drop;
+//!# extern crate hbbft;
+//!# extern crate rand;
+//!# fn main() {
+//!#
+//! use clear_on_drop::ClearOnDrop;
+//! use hbbft::broadcast::Broadcast;
+//! use hbbft::crypto::SecretKeySet;
+//! use hbbft::messaging::{DistAlgorithm, NetworkInfo, Target, TargetedMessage};
+//! use rand::{Rng, thread_rng};
+//! use std::collections::{BTreeSet, BTreeMap};
+//! use std::sync::Arc;
+//!
+//! // In the example, we will "simulate" a network by passing messages by hand between
+//! // instantiated nodes. We use u64 as network ids, and start by creating a common
+//! // network info.
+//!
+//! // Our simulated network will use seven nodes in total, node 3 will be the proposer.
+//! const NUM_NODES: u64 = 7;
+//! const PROPOSER_ID: u64 = 3;
+//!
+//! // Create set of node ids.
+//! let all_uids: BTreeSet<_> = (0..NUM_NODES).collect();
+//!
+//! // Secret keys are required to complete the NetworkInfo structure, but not used in the
+//! // broadcast algorithm.
+//! let mut rng = thread_rng();
+//! let secret_keys = SecretKeySet::random(4, &mut rng);
+//!
+//! // Create initial nodes by instantiating a `NetworkInfo` for each:
+//! let mut nodes: BTreeMap<_, _> = all_uids.iter().cloned().map(|i| {
+//!     let netinfo = NetworkInfo::new(
+//!         i,
+//!         all_uids.clone(),
+//!         secret_keys.secret_key_share(i),
+//!         secret_keys.public_keys(),
+//!     );
+//!
+//!     let bc = Broadcast::new(Arc::new(netinfo), PROPOSER_ID)
+//!                  .expect("could not instantiate Broadcast");
+//!
+//!     (i, bc)
+//! }).collect();
+//!
+//! // We are ready to start. First we generate a payload to broadcast:
+//! let mut payload: Vec<_> = vec![0; 128];
+//! rng.fill_bytes(&mut payload[..]);
+//!
+//! // Now we can start the algorithm, its input is the payload to be broadcast.
+//! let mut next_message = {
+//!        let proposer = nodes.get_mut(&PROPOSER_ID).unwrap();
+//!        proposer.input(payload.clone()).unwrap();
+//!
+//!        // attach the sender to the resulting message
+//!        proposer.next_message().map(|tm| (PROPOSER_ID, tm))
+//! };
+//!
+//! // We can sanity-check that a message is scheduled by the proposer:
+//! assert!(next_message.is_some());
+//!
+//! // The network is simulated by passing messages around from node to node.
+//! while let Some((sender, TargetedMessage { target, message })) = next_message {
+//!     println!("Message [{:?} -> {:?}]: {:?}", sender, target, message);
+//!
+//!     match target {
+//!         Target::All => {
+//!             let msg = &message;
+//!             nodes.iter_mut()
+//!                  .for_each(|(_, node)| { node.handle_message(&sender, msg.clone())
+//!                                              .expect("could not handle message"); });
+//!         },
+//!         Target::Node(ref dest) => {
+//!             let dest_node = nodes.get_mut(dest).expect("destination node not found");
+//!             dest_node.handle_message(&sender, message)
+//!                      .expect("could not handle message");
+//!         },
+//!     }
+//!
+//!     // We have handled the message, now we check all nodes for new messages, in order:
+//!     next_message = nodes
+//!                        .iter_mut()
+//!                        .filter_map(|(&id, node)| node.next_message()
+//!                                                      .map(|tm| (id, tm)))
+//!                        .next();
+//! }
+//!
+//! // The algorithm output of every node will be the original payload.
+//! for (_, mut node) in nodes {
+//!     assert_eq!(node.next_output().expect("missing output"), payload);
+//! }
+//!# }
+//! ```
 
 use std::collections::{BTreeMap, VecDeque};
 use std::fmt::{self, Debug};
@@ -48,6 +144,7 @@ use std::sync::Arc;
 
 use byteorder::{BigEndian, ByteOrder};
 use merkle::{MerkleTree, Proof};
+use rand;
 use reed_solomon_erasure as rse;
 use reed_solomon_erasure::ReedSolomon;
 use ring::digest;
@@ -84,6 +181,29 @@ pub enum BroadcastMessage {
     Ready(Vec<u8>),
 }
 
+// A random generation impl is provided for test cases. Unfortunately `#[cfg(test)]` does not work
+// for integration tests.
+impl rand::Rand for BroadcastMessage {
+    fn rand<R: rand::Rng>(rng: &mut R) -> Self {
+        let message_type = *rng.choose(&["value", "echo", "ready"]).unwrap();
+
+        // Create a random buffer for our proof.
+        let mut buffer: [u8; 32] = [0; 32];
+        rng.fill_bytes(&mut buffer);
+
+        // Generate a dummy proof to fill broadcast messages with.
+        let tree = MerkleTree::from_vec(&digest::SHA256, vec![buffer.to_vec()]);
+        let proof = tree.gen_proof(buffer.to_vec()).unwrap();
+
+        match message_type {
+            "value" => BroadcastMessage::Value(proof),
+            "echo" => BroadcastMessage::Echo(proof),
+            "ready" => BroadcastMessage::Ready(b"dummy-ready".to_vec()),
+            _ => unreachable!(),
+        }
+    }
+}
+
 impl Debug for BroadcastMessage {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match *self {
diff --git a/src/common_coin.rs b/src/common_coin.rs
index 0939ae7..4d210b9 100644
--- a/src/common_coin.rs
+++ b/src/common_coin.rs
@@ -45,7 +45,7 @@ error_chain! {
     }
 }
 
-#[derive(Serialize, Deserialize, Clone, Debug, PartialEq)]
+#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Rand)]
 pub struct CommonCoinMessage(Signature);
 
 impl CommonCoinMessage {
diff --git a/src/common_subset.rs b/src/common_subset.rs
index 4dadeed..4936aed 100644
--- a/src/common_subset.rs
+++ b/src/common_subset.rs
@@ -32,6 +32,7 @@ use broadcast::{self, Broadcast, BroadcastMessage, BroadcastResult};
 use fault_log::FaultLog;
 use fmt::HexBytes;
 use messaging::{DistAlgorithm, NetworkInfo, TargetedMessage};
+use rand::Rand;
 
 error_chain!{
     types {
@@ -54,8 +55,8 @@ error_chain!{
 type ProposedValue = Vec<u8>;
 
 /// Message from Common Subset to remote nodes.
-#[derive(Serialize, Deserialize, Clone, Debug)]
-pub enum Message<NodeUid> {
+#[derive(Serialize, Deserialize, Clone, Debug, Rand)]
+pub enum Message<NodeUid: Rand> {
     /// A message for the broadcast algorithm concerning the set element proposed by the given node.
     Broadcast(NodeUid, BroadcastMessage),
     /// A message for the agreement algorithm concerning the set element proposed by the given
@@ -65,9 +66,9 @@ pub enum Message<NodeUid> {
 
 /// The queue of outgoing messages in a `CommonSubset` instance.
 #[derive(Deref, DerefMut)]
-struct MessageQueue<NodeUid>(VecDeque<TargetedMessage<Message<NodeUid>, NodeUid>>);
+struct MessageQueue<NodeUid: Rand>(VecDeque<TargetedMessage<Message<NodeUid>, NodeUid>>);
 
-impl<NodeUid: Clone + Debug + Ord> MessageQueue<NodeUid> {
+impl<NodeUid: Clone + Debug + Ord + Rand> MessageQueue<NodeUid> {
     /// Appends to the queue the messages from `agr`, wrapped with `proposer_id`.
     fn extend_agreement(&mut self, proposer_id: &NodeUid, agr: &mut Agreement<NodeUid>) {
         let convert = |msg: TargetedMessage<AgreementMessage, NodeUid>| {
@@ -86,7 +87,7 @@ impl<NodeUid: Clone + Debug + Ord> MessageQueue<NodeUid> {
 }
 
 /// Asynchronous Common Subset algorithm instance
-pub struct CommonSubset<NodeUid> {
+pub struct CommonSubset<NodeUid: Rand> {
     /// Shared network information.
     netinfo: Arc<NetworkInfo<NodeUid>>,
     broadcast_instances: BTreeMap<NodeUid, Broadcast<NodeUid>>,
@@ -101,7 +102,7 @@ pub struct CommonSubset<NodeUid> {
     decided: bool,
 }
 
-impl<NodeUid: Clone + Debug + Ord> DistAlgorithm for CommonSubset<NodeUid> {
+impl<NodeUid: Clone + Debug + Ord + Rand> DistAlgorithm for CommonSubset<NodeUid> {
     type NodeUid = NodeUid;
     type Input = ProposedValue;
     type Output = BTreeMap<NodeUid, ProposedValue>;
@@ -145,7 +146,7 @@ impl<NodeUid: Clone + Debug + Ord> DistAlgorithm for CommonSubset<NodeUid> {
     }
 }
 
-impl<NodeUid: Clone + Debug + Ord> CommonSubset<NodeUid> {
+impl<NodeUid: Clone + Debug + Ord + Rand> CommonSubset<NodeUid> {
     pub fn new(netinfo: Arc<NetworkInfo<NodeUid>>, session_id: u64) -> CommonSubsetResult<Self> {
         // Create all broadcast instances.
         let mut broadcast_instances: BTreeMap<NodeUid, Broadcast<NodeUid>> = BTreeMap::new();
diff --git a/src/crypto/mod.rs b/src/crypto/mod.rs
index d25a40d..a5ce582 100644
--- a/src/crypto/mod.rs
+++ b/src/crypto/mod.rs
@@ -16,7 +16,7 @@ use clear_on_drop::ClearOnDrop;
 use init_with::InitWith;
 use pairing::bls12_381::{Bls12, Fr, FrRepr, G1, G1Affine, G2, G2Affine};
 use pairing::{CurveAffine, CurveProjective, Engine, Field, PrimeField};
-use rand::{ChaChaRng, OsRng, Rand, Rng, SeedableRng};
+use rand::{ChaChaRng, OsRng, Rng, SeedableRng};
 use ring::digest;
 
 use self::error::{ErrorKind, Result};
@@ -83,7 +83,8 @@ impl PublicKey {
 }
 
 /// A signature, or a signature share.
-#[derive(Deserialize, Serialize, Clone, PartialEq, Eq)]
+// note: random signatures can be generated for testing
+#[derive(Deserialize, Serialize, Clone, PartialEq, Eq, Rand)]
 pub struct Signature(#[serde(with = "serde_impl::projective")] G2);
 
 impl fmt::Debug for Signature {
@@ -112,7 +113,7 @@ impl Signature {
 }
 
 /// A secret key, or a secret key share.
-#[derive(Clone, PartialEq, Eq)]
+#[derive(Clone, PartialEq, Eq, Rand)]
 pub struct SecretKey(Fr);
 
 impl fmt::Debug for SecretKey {
@@ -129,12 +130,6 @@ impl Default for SecretKey {
     }
 }
 
-impl Rand for SecretKey {
-    fn rand<R: Rng>(rng: &mut R) -> Self {
-        SecretKey(rng.gen())
-    }
-}
-
 impl SecretKey {
     /// Creates a secret key from an existing value
     pub fn from_value(f: Fr) -> Self {
@@ -203,7 +198,7 @@ impl Ciphertext {
 }
 
 /// A decryption share. A threshold of decryption shares can be used to decrypt a message.
-#[derive(Clone, Deserialize, Serialize, Debug, PartialEq, Eq)]
+#[derive(Clone, Deserialize, Serialize, Debug, PartialEq, Eq, Rand)]
 pub struct DecryptionShare(#[serde(with = "serde_impl::projective")] G1);
 
 impl Hash for DecryptionShare {
diff --git a/src/dynamic_honey_badger/batch.rs b/src/dynamic_honey_badger/batch.rs
index e0a4ecb..4271948 100644
--- a/src/dynamic_honey_badger/batch.rs
+++ b/src/dynamic_honey_badger/batch.rs
@@ -1,4 +1,5 @@
 use super::ChangeState;
+use rand::Rand;
 use std::collections::BTreeMap;
 
 /// A batch of transactions the algorithm has output.
@@ -13,7 +14,7 @@ pub struct Batch<C, NodeUid> {
     pub change: ChangeState<NodeUid>,
 }
 
-impl<C, NodeUid: Ord> Batch<C, NodeUid> {
+impl<C, NodeUid: Ord + Rand> Batch<C, NodeUid> {
     /// Returns a new, empty batch with the given epoch.
     pub fn new(epoch: u64) -> Self {
         Batch {
diff --git a/src/dynamic_honey_badger/builder.rs b/src/dynamic_honey_badger/builder.rs
index aff47fc..2be5b1f 100644
--- a/src/dynamic_honey_badger/builder.rs
+++ b/src/dynamic_honey_badger/builder.rs
@@ -4,6 +4,7 @@ use std::hash::Hash;
 use std::marker::PhantomData;
 use std::sync::Arc;
 
+use rand::Rand;
 use serde::{Deserialize, Serialize};
 
 use super::{DynamicHoneyBadger, MessageQueue, VoteCounter};
@@ -25,7 +26,7 @@ pub struct DynamicHoneyBadgerBuilder<C, NodeUid> {
 impl<C, NodeUid> DynamicHoneyBadgerBuilder<C, NodeUid>
 where
     C: Eq + Serialize + for<'r> Deserialize<'r> + Debug + Hash,
-    NodeUid: Eq + Ord + Clone + Debug + Serialize + for<'r> Deserialize<'r> + Hash,
+    NodeUid: Eq + Ord + Clone + Debug + Serialize + for<'r> Deserialize<'r> + Hash + Rand,
 {
     /// Returns a new `DynamicHoneyBadgerBuilder` configured to use the node IDs and cryptographic
     /// keys specified by `netinfo`.
diff --git a/src/dynamic_honey_badger/mod.rs b/src/dynamic_honey_badger/mod.rs
index cf5b748..e3fdfbd 100644
--- a/src/dynamic_honey_badger/mod.rs
+++ b/src/dynamic_honey_badger/mod.rs
@@ -44,6 +44,7 @@
 //! `SyncKeyGen` instance is dropped, and a new one is started to create keys according to the new
 //! pending change.
 
+use rand::Rand;
 use std::collections::VecDeque;
 use std::fmt::Debug;
 use std::hash::Hash;
@@ -84,7 +85,7 @@ pub enum Input<C, NodeUid> {
 }
 
 /// A Honey Badger instance that can handle adding and removing nodes.
-pub struct DynamicHoneyBadger<C, NodeUid>
+pub struct DynamicHoneyBadger<C, NodeUid: Rand>
 where
     C: Eq + Serialize + for<'r> Deserialize<'r> + Debug + Hash,
     NodeUid: Ord + Clone + Serialize + for<'r> Deserialize<'r> + Debug,
@@ -114,7 +115,7 @@ where
 impl<C, NodeUid> DistAlgorithm for DynamicHoneyBadger<C, NodeUid>
 where
     C: Eq + Serialize + for<'r> Deserialize<'r> + Debug + Hash,
-    NodeUid: Eq + Ord + Clone + Serialize + for<'r> Deserialize<'r> + Debug + Hash,
+    NodeUid: Eq + Ord + Clone + Serialize + for<'r> Deserialize<'r> + Debug + Hash + Rand,
 {
     type NodeUid = NodeUid;
     type Input = Input<C, NodeUid>;
@@ -178,7 +179,7 @@ where
 impl<C, NodeUid> DynamicHoneyBadger<C, NodeUid>
 where
     C: Eq + Serialize + for<'r> Deserialize<'r> + Debug + Hash,
-    NodeUid: Eq + Ord + Clone + Debug + Serialize + for<'r> Deserialize<'r> + Hash,
+    NodeUid: Eq + Ord + Clone + Debug + Serialize + for<'r> Deserialize<'r> + Hash + Rand,
 {
     /// Returns a new `DynamicHoneyBadgerBuilder` configured to use the node IDs and cryptographic
     /// keys specified by `netinfo`.
@@ -487,7 +488,7 @@ pub enum KeyGenMessage {
 
 /// A message sent to or received from another node's Honey Badger instance.
 #[derive(Serialize, Deserialize, Debug, Clone)]
-pub enum Message<NodeUid> {
+pub enum Message<NodeUid: Rand> {
     /// A message belonging to the `HoneyBadger` algorithm started in the given epoch.
     HoneyBadger(u64, HbMessage<NodeUid>),
     /// A transaction to be committed, signed by a node.
@@ -496,7 +497,7 @@ pub enum Message<NodeUid> {
     SignedVote(SignedVote<NodeUid>),
 }
 
-impl<NodeUid> Message<NodeUid> {
+impl<NodeUid: Rand> Message<NodeUid> {
     fn start_epoch(&self) -> u64 {
         match *self {
             Message::HoneyBadger(epoch, _) => epoch,
@@ -516,11 +517,11 @@ impl<NodeUid> Message<NodeUid> {
 
 /// The queue of outgoing messages in a `HoneyBadger` instance.
 #[derive(Deref, DerefMut)]
-struct MessageQueue<NodeUid>(VecDeque<TargetedMessage<Message<NodeUid>, NodeUid>>);
+struct MessageQueue<NodeUid: Rand>(VecDeque<TargetedMessage<Message<NodeUid>, NodeUid>>);
 
 impl<NodeUid> MessageQueue<NodeUid>
 where
-    NodeUid: Eq + Hash + Ord + Clone + Debug + Serialize + for<'r> Deserialize<'r>,
+    NodeUid: Eq + Hash + Ord + Clone + Debug + Serialize + for<'r> Deserialize<'r> + Rand,
 {
     /// Appends to the queue the messages from `hb`, wrapped with `epoch`.
     fn extend_with_epoch<Tx>(&mut self, epoch: u64, hb: &mut HoneyBadger<Tx, NodeUid>)
diff --git a/src/dynamic_honey_badger/votes.rs b/src/dynamic_honey_badger/votes.rs
index c0edaf8..7addac9 100644
--- a/src/dynamic_honey_badger/votes.rs
+++ b/src/dynamic_honey_badger/votes.rs
@@ -85,7 +85,7 @@ where
 
     /// Returns an iterator over all pending votes that are newer than their voter's committed
     /// vote.
-    pub fn pending_votes<'a>(&'a self) -> impl Iterator<Item = &'a SignedVote<NodeUid>> {
+    pub fn pending_votes(&self) -> impl Iterator<Item = &SignedVote<NodeUid>> {
         self.pending.values().filter(move |signed_vote| {
             self.committed
                 .get(&signed_vote.voter)
diff --git a/src/honey_badger.rs b/src/honey_badger.rs
index 49e6dbe..19d3485 100644
--- a/src/honey_badger.rs
+++ b/src/honey_badger.rs
@@ -1,3 +1,4 @@
+use rand::Rand;
 use std::collections::btree_map::Entry;
 use std::collections::{BTreeMap, BTreeSet, VecDeque};
 use std::fmt::Debug;
@@ -44,7 +45,7 @@ pub struct HoneyBadgerBuilder<C, NodeUid> {
 impl<C, NodeUid> HoneyBadgerBuilder<C, NodeUid>
 where
     C: Serialize + for<'r> Deserialize<'r> + Debug + Hash + Eq,
-    NodeUid: Ord + Clone + Debug,
+    NodeUid: Ord + Clone + Debug + Rand,
 {
     /// Returns a new `HoneyBadgerBuilder` configured to use the node IDs and cryptographic keys
     /// specified by `netinfo`.
@@ -81,7 +82,7 @@ where
 }
 
 /// An instance of the Honey Badger Byzantine fault tolerant consensus algorithm.
-pub struct HoneyBadger<C, NodeUid> {
+pub struct HoneyBadger<C, NodeUid: Rand> {
     /// Shared network data.
     netinfo: Arc<NetworkInfo<NodeUid>>,
     /// The earliest epoch from which we have not yet received output.
@@ -112,7 +113,7 @@ pub struct HoneyBadger<C, NodeUid> {
 impl<C, NodeUid> DistAlgorithm for HoneyBadger<C, NodeUid>
 where
     C: Serialize + for<'r> Deserialize<'r> + Debug + Hash + Eq,
-    NodeUid: Ord + Clone + Debug,
+    NodeUid: Ord + Clone + Debug + Rand,
 {
     type NodeUid = NodeUid;
     type Input = C;
@@ -168,7 +169,7 @@ where
 impl<C, NodeUid> HoneyBadger<C, NodeUid>
 where
     C: Serialize + for<'r> Deserialize<'r> + Debug + Hash + Eq,
-    NodeUid: Ord + Clone + Debug,
+    NodeUid: Ord + Clone + Debug + Rand,
 {
     /// Returns a new `HoneyBadgerBuilder` configured to use the node IDs and cryptographic keys
     /// specified by `netinfo`.
@@ -634,8 +635,8 @@ impl<C, NodeUid: Ord> Batch<C, NodeUid> {
 }
 
 /// The content of a `HoneyBadger` message. It should be further annotated with an epoch.
-#[derive(Clone, Debug, Deserialize, Serialize)]
-pub enum MessageContent<NodeUid> {
+#[derive(Clone, Debug, Deserialize, Rand, Serialize)]
+pub enum MessageContent<NodeUid: Rand> {
     /// A message belonging to the common subset algorithm in the given epoch.
     CommonSubset(common_subset::Message<NodeUid>),
     /// A decrypted share of the output of `proposer_id`.
@@ -645,7 +646,7 @@ pub enum MessageContent<NodeUid> {
     },
 }
 
-impl<NodeUid> MessageContent<NodeUid> {
+impl<NodeUid: Rand> MessageContent<NodeUid> {
     pub fn with_epoch(self, epoch: u64) -> Message<NodeUid> {
         Message {
             epoch,
@@ -655,13 +656,13 @@ impl<NodeUid> MessageContent<NodeUid> {
 }
 
 /// A message sent to or received from another node's Honey Badger instance.
-#[derive(Clone, Debug, Deserialize, Serialize)]
-pub struct Message<NodeUid> {
+#[derive(Clone, Debug, Deserialize, Rand, Serialize)]
+pub struct Message<NodeUid: Rand> {
     epoch: u64,
     content: MessageContent<NodeUid>,
 }
 
-impl<NodeUid> Message<NodeUid> {
+impl<NodeUid: Rand> Message<NodeUid> {
     pub fn epoch(&self) -> u64 {
         self.epoch
     }
@@ -669,9 +670,9 @@ impl<NodeUid> Message<NodeUid> {
 
 /// The queue of outgoing messages in a `HoneyBadger` instance.
 #[derive(Deref, DerefMut)]
-struct MessageQueue<NodeUid>(VecDeque<TargetedMessage<Message<NodeUid>, NodeUid>>);
+struct MessageQueue<NodeUid: Rand>(VecDeque<TargetedMessage<Message<NodeUid>, NodeUid>>);
 
-impl<NodeUid: Clone + Debug + Ord> MessageQueue<NodeUid> {
+impl<NodeUid: Clone + Debug + Ord + Rand> MessageQueue<NodeUid> {
     /// Appends to the queue the messages from `cs`, wrapped with `epoch`.
     fn extend_with_epoch(&mut self, epoch: u64, cs: &mut CommonSubset<NodeUid>) {
         let convert = |msg: TargetedMessage<common_subset::Message<NodeUid>, NodeUid>| {
diff --git a/src/lib.rs b/src/lib.rs
index e815b87..8e14f0a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -114,6 +114,8 @@ extern crate pairing;
 #[cfg(feature = "serialization-protobuf")]
 extern crate protobuf;
 extern crate rand;
+#[macro_use]
+extern crate rand_derive;
 extern crate reed_solomon_erasure;
 extern crate ring;
 extern crate serde;
diff --git a/src/queueing_honey_badger.rs b/src/queueing_honey_badger.rs
index 90aceee..84a6644 100644
--- a/src/queueing_honey_badger.rs
+++ b/src/queueing_honey_badger.rs
@@ -8,6 +8,7 @@ use std::fmt::Debug;
 use std::hash::Hash;
 use std::marker::PhantomData;
 
+use rand::Rand;
 use serde::{Deserialize, Serialize};
 
 use dynamic_honey_badger::{self, Batch as DhbBatch, DynamicHoneyBadger, Message};
@@ -40,7 +41,7 @@ pub struct QueueingHoneyBadgerBuilder<Tx, NodeUid> {
 impl<Tx, NodeUid> QueueingHoneyBadgerBuilder<Tx, NodeUid>
 where
     Tx: Eq + Serialize + for<'r> Deserialize<'r> + Debug + Hash + Clone,
-    NodeUid: Eq + Ord + Clone + Debug + Serialize + for<'r> Deserialize<'r> + Hash,
+    NodeUid: Eq + Ord + Clone + Debug + Serialize + for<'r> Deserialize<'r> + Hash + Rand,
 {
     /// Returns a new `QueueingHoneyBadgerBuilder` configured to use the node IDs and cryptographic
     /// keys specified by `netinfo`.
@@ -110,7 +111,7 @@ where
 pub struct QueueingHoneyBadger<Tx, NodeUid>
 where
     Tx: Eq + Serialize + for<'r> Deserialize<'r> + Debug + Hash,
-    NodeUid: Ord + Clone + Serialize + for<'r> Deserialize<'r> + Debug,
+    NodeUid: Ord + Clone + Serialize + for<'r> Deserialize<'r> + Debug + Rand,
 {
     /// The target number of transactions to be included in each batch.
     batch_size: usize,
@@ -125,7 +126,7 @@ where
 impl<Tx, NodeUid> DistAlgorithm for QueueingHoneyBadger<Tx, NodeUid>
 where
     Tx: Eq + Serialize + for<'r> Deserialize<'r> + Debug + Hash + Clone,
-    NodeUid: Eq + Ord + Clone + Serialize + for<'r> Deserialize<'r> + Debug + Hash,
+    NodeUid: Eq + Ord + Clone + Serialize + for<'r> Deserialize<'r> + Debug + Hash + Rand,
 {
     type NodeUid = NodeUid;
     type Input = Input<Tx, NodeUid>;
@@ -179,7 +180,7 @@ where
 impl<Tx, NodeUid> QueueingHoneyBadger<Tx, NodeUid>
 where
     Tx: Eq + Serialize + for<'r> Deserialize<'r> + Debug + Hash + Clone,
-    NodeUid: Eq + Ord + Clone + Debug + Serialize + for<'r> Deserialize<'r> + Hash,
+    NodeUid: Eq + Ord + Clone + Debug + Serialize + for<'r> Deserialize<'r> + Hash + Rand,
 {
     /// Returns a new `QueueingHoneyBadgerBuilder` configured to use the node IDs and cryptographic
     /// keys specified by `netinfo`.
@@ -187,6 +188,11 @@ where
         QueueingHoneyBadgerBuilder::new(netinfo)
     }
 
+    /// Returns a reference to the internal `DynamicHoneyBadger` instance.
+    pub fn dyn_hb(&self) -> &DynamicHoneyBadger<Vec<Tx>, NodeUid> {
+        &self.dyn_hb
+    }
+
     /// Initiates the next epoch by proposing a batch from the queue.
     fn propose(&mut self) -> Result<FaultLog<NodeUid>> {
         let amount = cmp::max(1, self.batch_size / self.dyn_hb.netinfo().num_nodes());
diff --git a/tests/agreement.rs b/tests/agreement.rs
index 4f9b52f..e40fee1 100644
--- a/tests/agreement.rs
+++ b/tests/agreement.rs
@@ -21,6 +21,8 @@ extern crate pairing;
 extern crate rand;
 #[macro_use]
 extern crate serde_derive;
+#[macro_use]
+extern crate rand_derive;
 
 mod network;
 
diff --git a/tests/broadcast.rs b/tests/broadcast.rs
index 4103097..7f10d0e 100644
--- a/tests/broadcast.rs
+++ b/tests/broadcast.rs
@@ -8,6 +8,8 @@ extern crate pairing;
 extern crate rand;
 #[macro_use]
 extern crate serde_derive;
+#[macro_use]
+extern crate rand_derive;
 
 mod network;
 
@@ -19,8 +21,11 @@ use rand::Rng;
 
 use hbbft::broadcast::{Broadcast, BroadcastMessage};
 use hbbft::crypto::SecretKeySet;
-use hbbft::messaging::{DistAlgorithm, NetworkInfo, TargetedMessage};
-use network::{Adversary, MessageScheduler, NodeUid, SilentAdversary, TestNetwork, TestNode};
+use hbbft::messaging::{DistAlgorithm, NetworkInfo, Target, TargetedMessage};
+use network::{
+    Adversary, MessageScheduler, MessageWithSender, NodeUid, RandomAdversary, SilentAdversary,
+    TestNetwork, TestNode,
+};
 
 /// An adversary that inputs an alternate value.
 struct ProposeAdversary {
@@ -55,7 +60,7 @@ impl Adversary<Broadcast<NodeUid>> for ProposeAdversary {
         // All messages are ignored.
     }
 
-    fn step(&mut self) -> Vec<(NodeUid, TargetedMessage<BroadcastMessage, NodeUid>)> {
+    fn step(&mut self) -> Vec<MessageWithSender<Broadcast<NodeUid>>> {
         if self.has_sent {
             return vec![];
         }
@@ -84,7 +89,9 @@ impl Adversary<Broadcast<NodeUid>> for ProposeAdversary {
         ));
         let mut bc = Broadcast::new(netinfo, id).expect("broadcast instance");
         bc.input(b"Fake news".to_vec()).expect("propose");
-        bc.message_iter().map(|msg| (id, msg)).collect()
+        bc.message_iter()
+            .map(|msg| MessageWithSender::new(id, msg))
+            .collect()
     }
 }
 
@@ -182,3 +189,15 @@ fn test_broadcast_first_delivery_adv_propose() {
     };
     test_broadcast_different_sizes(new_adversary, b"Foo");
 }
+
+#[test]
+fn test_broadcast_random_adversary() {
+    let new_adversary = |_, _| {
+        // Note: Set this to 0.8 to watch 30 gigs of RAM disappear.
+        RandomAdversary::new(0.2, 0.2, || TargetedMessage {
+            target: Target::All,
+            message: rand::random(),
+        })
+    };
+    test_broadcast_different_sizes(new_adversary, b"RandomFoo");
+}
diff --git a/tests/common_coin.rs b/tests/common_coin.rs
index 7b0e9d3..23ab884 100644
--- a/tests/common_coin.rs
+++ b/tests/common_coin.rs
@@ -8,6 +8,8 @@ extern crate pairing;
 extern crate rand;
 #[macro_use]
 extern crate serde_derive;
+#[macro_use]
+extern crate rand_derive;
 
 mod network;
 
diff --git a/tests/common_subset.rs b/tests/common_subset.rs
index 658bd93..7af95c7 100644
--- a/tests/common_subset.rs
+++ b/tests/common_subset.rs
@@ -8,6 +8,8 @@ extern crate pairing;
 extern crate rand;
 #[macro_use]
 extern crate serde_derive;
+#[macro_use]
+extern crate rand_derive;
 
 mod network;
 
diff --git a/tests/dynamic_honey_badger.rs b/tests/dynamic_honey_badger.rs
index d053591..cbdbcba 100644
--- a/tests/dynamic_honey_badger.rs
+++ b/tests/dynamic_honey_badger.rs
@@ -8,6 +8,8 @@ extern crate pairing;
 extern crate rand;
 #[macro_use]
 extern crate serde_derive;
+#[macro_use]
+extern crate rand_derive;
 
 mod network;
 
diff --git a/tests/honey_badger.rs b/tests/honey_badger.rs
index 8b3a58b..fdc71b7 100644
--- a/tests/honey_badger.rs
+++ b/tests/honey_badger.rs
@@ -8,6 +8,8 @@ extern crate env_logger;
 extern crate pairing;
 extern crate rand;
 #[macro_use]
+extern crate rand_derive;
+#[macro_use]
 extern crate serde_derive;
 
 mod network;
@@ -22,7 +24,8 @@ use hbbft::messaging::{NetworkInfo, Target, TargetedMessage};
 use hbbft::transaction_queue::TransactionQueue;
 
 use network::{
-    Adversary, MessageScheduler, MessageWithSender, NodeUid, SilentAdversary, TestNetwork, TestNode,
+    Adversary, MessageScheduler, MessageWithSender, NodeUid, RandomAdversary, SilentAdversary,
+    TestNetwork, TestNode,
 };
 
 type UsizeHoneyBadger = HoneyBadger<Vec<usize>, NodeUid>;
@@ -99,7 +102,7 @@ impl Adversary<UsizeHoneyBadger> for FaultyShareAdversary {
                         .expect("decryption share");
                     // Send the share to remote nodes.
                     for proposer_id in 0..self.num_good + self.num_adv {
-                        outgoing.push((
+                        outgoing.push(MessageWithSender::new(
                             NodeUid(sender_id),
                             Target::All.message(
                                 MessageContent::DecryptionShare {
@@ -237,3 +240,15 @@ fn test_honey_badger_faulty_share() {
     };
     test_honey_badger_different_sizes(new_adversary, 8);
 }
+
+#[test]
+fn test_honey_badger_random_adversary() {
+    let new_adversary = |_, _, _| {
+        // A 10% injection chance is roughly ~13k extra messages added.
+        RandomAdversary::new(0.1, 0.1, || TargetedMessage {
+            target: Target::All,
+            message: rand::random(),
+        })
+    };
+    test_honey_badger_different_sizes(new_adversary, 8);
+}
diff --git a/tests/network/mod.rs b/tests/network/mod.rs
index 714643d..821aa01 100644
--- a/tests/network/mod.rs
+++ b/tests/network/mod.rs
@@ -1,6 +1,6 @@
 use std::collections::{BTreeMap, BTreeSet, VecDeque};
-use std::fmt::Debug;
-use std::hash::Hash;
+use std::fmt::{self, Debug};
+use std::mem;
 use std::sync::Arc;
 
 use rand::{self, Rng};
@@ -9,7 +9,7 @@ use hbbft::crypto::{PublicKeySet, SecretKeySet};
 use hbbft::messaging::{DistAlgorithm, NetworkInfo, Target, TargetedMessage};
 
 /// A node identifier. In the tests, nodes are simply numbered.
-#[derive(Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Clone, Copy, Serialize, Deserialize)]
+#[derive(Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Clone, Copy, Serialize, Deserialize, Rand)]
 pub struct NodeUid(pub usize);
 
 /// A "node" running an instance of the algorithm `D`.
@@ -68,6 +68,11 @@ impl<D: DistAlgorithm> TestNode<D> {
             .expect("handling message");
         self.outputs.extend(self.algo.output_iter());
     }
+
+    /// Checks whether the node has messages to process
+    fn is_idle(&self) -> bool {
+        self.queue.is_empty()
+    }
 }
 
 /// A strategy for picking the next good node to handle a message.
@@ -105,21 +110,61 @@ impl MessageScheduler {
     }
 }
 
-pub type MessageWithSender<D> = (
-    <D as DistAlgorithm>::NodeUid,
-    TargetedMessage<<D as DistAlgorithm>::Message, <D as DistAlgorithm>::NodeUid>,
-);
+/// A message combined with a sender.
+pub struct MessageWithSender<D: DistAlgorithm> {
+    /// The sender of the message.
+    pub sender: <D as DistAlgorithm>::NodeUid,
+    /// The targeted message (recipient and message body).
+    pub tm: TargetedMessage<<D as DistAlgorithm>::Message, <D as DistAlgorithm>::NodeUid>,
+}
+
+// The Debug implementation cannot be derived automatically, possibly due to a compiler bug. For
+// this reason, it is implemented manually here.
+impl<D: DistAlgorithm> fmt::Debug for MessageWithSender<D> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(
+            f,
+            "MessageWithSender {{ sender: {:?}, tm: {:?} }}",
+            self.sender, self.tm.target
+        )
+    }
+}
+
+impl<D: DistAlgorithm> MessageWithSender<D> {
+    /// Creates a new message with a sender.
+    pub fn new(
+        sender: D::NodeUid,
+        tm: TargetedMessage<D::Message, D::NodeUid>,
+    ) -> MessageWithSender<D> {
+        MessageWithSender { sender, tm }
+    }
+}
 
 /// An adversary that can control a set of nodes and pick the next good node to receive a message.
+///
+/// See `TestNetwork::step()` for a more detailed description of its capabilities.
 pub trait Adversary<D: DistAlgorithm> {
     /// Chooses a node to be the next one to handle a message.
+    ///
+    /// Starvation is illegal, i.e. in every iteration a node that has pending incoming messages
+    /// must be chosen.
     fn pick_node(&self, nodes: &BTreeMap<D::NodeUid, TestNode<D>>) -> D::NodeUid;
 
-    /// Adds a message sent to one of the adversary's nodes.
+    /// Called when a node controlled by the adversary receives a message.
     fn push_message(&mut self, sender_id: D::NodeUid, msg: TargetedMessage<D::Message, D::NodeUid>);
 
     /// Produces a list of messages to be sent from the adversary's nodes.
     fn step(&mut self) -> Vec<MessageWithSender<D>>;
+
+    /// Initialize an adversary. This function's primary purpose is to inform the adversary over
+    /// some aspects of the network, such as which nodes they control.
+    fn init(
+        &mut self,
+        _all_nodes: &BTreeMap<D::NodeUid, TestNode<D>>,
+        _adv_nodes: &BTreeMap<D::NodeUid, Arc<NetworkInfo<D::NodeUid>>>,
+    ) {
+        // default: does nothing
+    }
 }
 
 /// An adversary whose nodes never send any messages.
@@ -148,11 +193,165 @@ impl<D: DistAlgorithm> Adversary<D> for SilentAdversary {
     }
 }
 
-/// A collection of `TestNode`s representing a network.
-pub struct TestNetwork<A: Adversary<D>, D: DistAlgorithm>
-where
-    <D as DistAlgorithm>::NodeUid: Hash,
+/// Return true with a certain `probability` ([0 .. 1.0]).
+fn randomly(probability: f32) -> bool {
+    assert!(probability <= 1.0);
+    assert!(probability >= 0.0);
+
+    let mut rng = rand::thread_rng();
+    rng.gen_range(0.0, 1.0) <= probability
+}
+
+#[test]
+fn test_randomly() {
+    assert!(randomly(1.0));
+    assert!(!randomly(0.0));
+}
+
+/// An adversary that performs naive replay attacks.
+///
+/// The adversary will randomly take a message that is sent to one of its nodes and re-send it to
+/// a different node. Additionally, it will inject unrelated messages at random.
+#[allow(unused)] // not used in all tests
+pub struct RandomAdversary<D: DistAlgorithm, F> {
+    /// The underlying scheduler used
+    scheduler: MessageScheduler,
+
+    /// Node ids seen by the adversary.
+    known_node_ids: Vec<D::NodeUid>,
+    /// Node ids under control of adversary
+    known_adversarial_ids: Vec<D::NodeUid>,
+
+    /// Internal queue for messages to be returned on the next `Adversary::step()` call
+    outgoing: Vec<MessageWithSender<D>>,
+    /// Generates random messages to be injected
+    generator: F,
+
+    /// Probability of a message replay
+    p_replay: f32,
+    /// Probability of a message injection
+    p_inject: f32,
+}
+
+impl<D: DistAlgorithm, F> RandomAdversary<D, F> {
+    /// Creates a new random adversary instance.
+    #[allow(unused)]
+    pub fn new(p_replay: f32, p_inject: f32, generator: F) -> RandomAdversary<D, F> {
+        assert!(
+            p_inject < 0.95,
+            "injections are repeated, p_inject must be smaller than 0.95"
+        );
+
+        RandomAdversary {
+            // The random adversary, true to its name, always schedules randomly.
+            scheduler: MessageScheduler::Random,
+            known_node_ids: Vec::new(),
+            known_adversarial_ids: Vec::new(),
+            outgoing: Vec::new(),
+            generator,
+            p_replay,
+            p_inject,
+        }
+    }
+}
+
+impl<D: DistAlgorithm, F: Fn() -> TargetedMessage<D::Message, D::NodeUid>> Adversary<D>
+    for RandomAdversary<D, F>
 {
+    fn init(
+        &mut self,
+        all_nodes: &BTreeMap<D::NodeUid, TestNode<D>>,
+        nodes: &BTreeMap<D::NodeUid, Arc<NetworkInfo<D::NodeUid>>>,
+    ) {
+        self.known_adversarial_ids = nodes.keys().cloned().collect();
+        self.known_node_ids = all_nodes.keys().cloned().collect();
+    }
+
+    fn pick_node(&self, nodes: &BTreeMap<D::NodeUid, TestNode<D>>) -> D::NodeUid {
+        // Just let the scheduler pick a node.
+        self.scheduler.pick_node(nodes)
+    }
+
+    fn push_message(&mut self, _: D::NodeUid, msg: TargetedMessage<D::Message, D::NodeUid>) {
+        // If we have not discovered the network topology yet, abort.
+        if self.known_node_ids.is_empty() {
+            return;
+        }
+
+        // only replay a message in some cases
+        if !randomly(self.p_replay) {
+            return;
+        }
+
+        let TargetedMessage { message, target } = msg;
+
+        match target {
+            Target::All => {
+                // Ideally, we would want to handle broadcast messages as well; however the
+                // adversary API is quite cumbersome at the moment in regards to access to the
+                // network topology. To re-send a broadcast message from one of the attacker
+                // controlled nodes, we would have to get a list of attacker controlled nodes
+                // here and use a random one as the origin/sender, this is not done here.
+                return;
+            }
+            Target::Node(our_node_id) => {
+                // Choose a new target to send the message to. The unwrap never fails, because we
+                // ensured that `known_node_ids` is non-empty earlier.
+                let mut rng = rand::thread_rng();
+                let new_target_node = rng.choose(&self.known_node_ids).unwrap().clone();
+
+                // TODO: We could randomly broadcast it instead, if we had access to topology
+                //       information.
+                self.outgoing.push(MessageWithSender::new(
+                    our_node_id,
+                    TargetedMessage {
+                        target: Target::Node(new_target_node),
+                        message,
+                    },
+                ));
+            }
+        }
+    }
+
+    fn step(&mut self) -> Vec<MessageWithSender<D>> {
+        // Clear messages.
+        let mut tmp = Vec::new();
+        mem::swap(&mut tmp, &mut self.outgoing);
+
+        // Possibly inject more messages:
+        while randomly(self.p_inject) {
+            let mut rng = rand::thread_rng();
+
+            // Pick a random adversarial node and create a message using the generator.
+            if let Some(sender) = rng.choose(&self.known_adversarial_ids[..]) {
+                let tm = (self.generator)();
+
+                // Add to outgoing queue.
+                tmp.push(MessageWithSender::new(sender.clone(), tm));
+            }
+        }
+
+        if !tmp.is_empty() {
+            println!("Injecting random messages: {:?}", tmp);
+        }
+        tmp
+    }
+}
+
+/// A collection of `TestNode`s representing a network.
+///
+/// Each `TestNetwork` type is tied to a specific adversary and a distributed algorithm. It consists
+/// of a set of nodes, some of which are controlled by the adversary and some of which may be
+/// observer nodes, as well as a set of threshold-cryptography public keys.
+///
+/// In addition to being able to participate correctly in the network using his nodes, the
+/// adversary can:
+///
+/// 1. Decide which node is the next one to make progress,
+/// 2. Send arbitrary messages to any node originating from one of the nodes they control.
+///
+/// See the `step` function for details on actual operation of the network.
+pub struct TestNetwork<A: Adversary<D>, D: DistAlgorithm> {
     pub nodes: BTreeMap<D::NodeUid, TestNode<D>>,
     pub observer: TestNode<D>,
     pub adv_nodes: BTreeMap<D::NodeUid, Arc<NetworkInfo<D::NodeUid>>>,
@@ -208,6 +407,7 @@ where
             .map(NodeUid)
             .map(new_adv_node_by_id)
             .collect();
+
         let mut network = TestNetwork {
             nodes: (0..good_num).map(NodeUid).map(new_node_by_id).collect(),
             observer: new_node_by_id(NodeUid(good_num + adv_num)).1,
@@ -215,9 +415,13 @@ where
             pk_set: pk_set.clone(),
             adv_nodes,
         };
+
+        // Inform the adversary about their nodes.
+        network.adversary.init(&network.nodes, &network.adv_nodes);
+
         let msgs = network.adversary.step();
-        for (sender_id, msg) in msgs {
-            network.dispatch_messages(sender_id, vec![msg]);
+        for MessageWithSender { sender, tm } in msgs {
+            network.dispatch_messages(sender, vec![tm]);
         }
         let mut initial_msgs: Vec<(D::NodeUid, Vec<_>)> = Vec::new();
         for (id, node) in &mut network.nodes {
@@ -266,20 +470,40 @@ where
         }
     }
 
-    /// Handles a queued message in a randomly selected node and returns the selected node's ID.
+    /// Performs one iteration of the network, consisting of the following steps:
+    ///
+    /// 1. Give the adversary a chance to send messages of his choosing through `Adversary::step()`,
+    /// 2. Let the adversary pick a node that receives its next message through
+    ///    `Adversary::pick_node()`.
+    ///
+    /// Returns the node ID of the node that made progress.
     pub fn step(&mut self) -> NodeUid {
+        // We let the adversary send out messages to any number of nodes.
         let msgs = self.adversary.step();
-        for (sender_id, msg) in msgs {
-            self.dispatch_messages(sender_id, Some(msg));
+        for MessageWithSender { sender, tm } in msgs {
+            self.dispatch_messages(sender, Some(tm));
         }
-        // Pick a random non-idle node..
+
+        // Now one node is chosen to make progress, we let the adversary decide which.
         let id = self.adversary.pick_node(&self.nodes);
+
+        // The node handles the incoming message and creates new outgoing ones to be dispatched.
         let msgs: Vec<_> = {
             let node = self.nodes.get_mut(&id).unwrap();
+
+            // Ensure the adversary is playing fair by selecting a node that will result in actual
+            // progress being made, otherwise `TestNode::handle_message()` will panic on `expect()`
+            // with a much more cryptic error message.
+            assert!(
+                !node.is_idle(),
+                "adversary illegally selected an idle node in pick_node()"
+            );
+
             node.handle_message();
             node.algo.message_iter().collect()
         };
         self.dispatch_messages(id, msgs);
+
         id
     }
 
diff --git a/tests/queueing_honey_badger.rs b/tests/queueing_honey_badger.rs
index f8a2ec0..b978ba7 100644
--- a/tests/queueing_honey_badger.rs
+++ b/tests/queueing_honey_badger.rs
@@ -8,6 +8,8 @@ extern crate pairing;
 extern crate rand;
 #[macro_use]
 extern crate serde_derive;
+#[macro_use]
+extern crate rand_derive;
 
 mod network;