diff --git a/core/src/lib.rs b/core/src/lib.rs
index 122823f2d..c530aefbd 100644
--- a/core/src/lib.rs
+++ b/core/src/lib.rs
@@ -50,6 +50,7 @@ pub mod rpc_subscriptions;
 pub mod sendmmsg;
 pub mod service;
 pub mod sigverify;
+pub mod sigverify_shreds;
 pub mod sigverify_stage;
 pub mod snapshot_packager_service;
 pub mod storage_stage;
diff --git a/core/src/sigverify.rs b/core/src/sigverify.rs
index 3a7751784..09d391a0f 100644
--- a/core/src/sigverify.rs
+++ b/core/src/sigverify.rs
@@ -24,6 +24,7 @@ use std::cell::RefCell;
 
 thread_local!(static PAR_THREAD_POOL: RefCell<ThreadPool> = RefCell::new(rayon::ThreadPoolBuilder::new()
                     .num_threads(get_thread_count())
+                    .thread_name(|ix| format!("sigverify_{}", ix))
                     .build()
                     .unwrap()));
 
@@ -114,7 +115,7 @@ fn verify_packet(packet: &Packet) -> u8 {
     1
 }
 
-fn batch_size(batches: &[Packets]) -> usize {
+pub fn batch_size(batches: &[Packets]) -> usize {
     batches.iter().map(|p| p.packets.len()).sum()
 }
 
@@ -271,6 +272,29 @@ pub fn ed25519_verify_disabled(batches: &[Packets]) -> Vec<Vec<u8>> {
     rv
 }
 
+pub fn copy_return_values(sig_lens: &[Vec<u32>], out: &PinnedVec<u8>, rvs: &mut Vec<Vec<u8>>) {
+    let mut num = 0;
+    for (vs, sig_vs) in rvs.iter_mut().zip(sig_lens.iter()) {
+        for (v, sig_v) in vs.iter_mut().zip(sig_vs.iter()) {
+            if *sig_v == 0 {
+                *v = 0;
+            } else {
+                let mut vout = 1;
+                for _ in 0..*sig_v {
+                    if 0 == out[num] {
+                        vout = 0;
+                    }
+                    num += 1;
+                }
+                *v = vout;
+            }
+            if *v != 0 {
+                trace!("VERIFIED PACKET!!!!!");
+            }
+        }
+    }
+}
+
 pub fn ed25519_verify(
     batches: &[Packets],
     recycler: &Recycler<TxOffset>,
@@ -340,26 +364,7 @@ pub fn ed25519_verify(
         }
     }
     trace!("done verify");
-    let mut num = 0;
-    for (vs, sig_vs) in rvs.iter_mut().zip(sig_lens.iter()) {
-        for (v, sig_v) in vs.iter_mut().zip(sig_vs.iter()) {
-            if *sig_v == 0 {
-                *v = 0;
-            } else {
-                let mut vout = 1;
-                for _ in 0..*sig_v {
-                    if 0 == out[num] {
-                        vout = 0;
-                    }
-                    num += 1;
-                }
-                *v = vout;
-            }
-            if *v != 0 {
-                trace!("VERIFIED PACKET!!!!!");
-            }
-        }
-    }
+    copy_return_values(&sig_lens, &out, &mut rvs);
     inc_new_counter_debug!("ed25519_verify_gpu", count);
     recycler_out.recycle(out);
     recycler.recycle(signature_offsets);
diff --git a/core/src/sigverify_shreds.rs b/core/src/sigverify_shreds.rs
new file mode 100644
index 000000000..c0d80905b
--- /dev/null
+++ b/core/src/sigverify_shreds.rs
@@ -0,0 +1,408 @@
+#![allow(clippy::implicit_hasher)]
+use crate::cuda_runtime::PinnedVec;
+use crate::packet::{Packet, Packets};
+use crate::recycler::Recycler;
+use crate::recycler::Reset;
+use crate::sigverify::{self, TxOffset};
+use bincode::deserialize;
+use rayon::iter::IntoParallelIterator;
+use rayon::iter::ParallelIterator;
+use rayon::ThreadPool;
+use solana_ledger::perf_libs;
+use solana_ledger::shred::ShredType;
+use solana_metrics::inc_new_counter_debug;
+use solana_rayon_threadlimit::get_thread_count;
+use solana_sdk::pubkey::Pubkey;
+use solana_sdk::signature::Signature;
+use std::collections::HashMap;
+use std::mem::size_of;
+
+use std::cell::RefCell;
+
+thread_local!(static PAR_THREAD_POOL: RefCell<ThreadPool> = RefCell::new(rayon::ThreadPoolBuilder::new()
+                    .num_threads(get_thread_count())
+                    .thread_name(|ix| format!("sigverify_shreds_{}", ix))
+                    .build()
+                    .unwrap()));
+
+impl Reset for PinnedVec<Pubkey> {
+    fn reset(&mut self) {
+        self.resize(0, Pubkey::default());
+    }
+}
+
+/// Assuming layout is
+/// signature: Signature
+/// signed_msg: {
+///   type: ShredType
+///   slot: u64,
+///   ...
+/// }
+/// Signature is the first thing in the packet, and slot is the first thing in the signed message.
+fn verify_shred_cpu(packet: &Packet, slot_leaders: &HashMap<u64, Pubkey>) -> Option<u8> {
+    let sig_start = 0;
+    let sig_end = size_of::<Signature>();
+    let slot_start = sig_end + size_of::<ShredType>();
+    let slot_end = slot_start + size_of::<u64>();
+    let msg_start = sig_end;
+    let msg_end = packet.meta.size;
+    trace!("slot start and end {} {}", slot_start, slot_end);
+    if packet.meta.size < slot_end {
+        return Some(0);
+    }
+    let slot: u64 = deserialize(&packet.data[slot_start..slot_end]).ok()?;
+    trace!("slot {}", slot);
+    let pubkey: &Pubkey = slot_leaders.get(&slot)?;
+    if packet.meta.size < sig_end {
+        return Some(0);
+    }
+    let signature = Signature::new(&packet.data[sig_start..sig_end]);
+    trace!("signature {}", signature);
+    if !signature.verify(pubkey.as_ref(), &packet.data[msg_start..msg_end]) {
+        return Some(0);
+    }
+    Some(1)
+}
+
+pub fn verify_shreds_cpu(batches: &[Packets], slot_leaders: &HashMap<u64, Pubkey>) -> Vec<Vec<u8>> {
+    use rayon::prelude::*;
+    let count = sigverify::batch_size(batches);
+    debug!("CPU SHRED ECDSA for {}", count);
+    let rv = PAR_THREAD_POOL.with(|thread_pool| {
+        thread_pool.borrow().install(|| {
+            batches
+                .into_par_iter()
+                .map(|p| {
+                    p.packets
+                        .par_iter()
+                        .map(|p| verify_shred_cpu(p, slot_leaders).unwrap_or(0))
+                        .collect()
+                })
+                .collect()
+        })
+    });
+    inc_new_counter_debug!("ed25519_shred_verify_cpu", count);
+    rv
+}
+
+fn shred_gpu_pubkeys(
+    batches: &[Packets],
+    slot_leaders: &HashMap<u64, Pubkey>,
+    recycler_offsets: &Recycler<TxOffset>,
+    recycler_pubkeys: &Recycler<PinnedVec<Pubkey>>,
+) -> (PinnedVec<Pubkey>, TxOffset, usize) {
+    //TODO: mark Pubkey::default shreds as failed after the GPU returns
+    assert_eq!(slot_leaders.get(&std::u64::MAX), Some(&Pubkey::default()));
+    let slots: Vec<Vec<u64>> = PAR_THREAD_POOL.with(|thread_pool| {
+        thread_pool.borrow().install(|| {
+            batches
+                .into_par_iter()
+                .map(|p| {
+                    p.packets
+                        .iter()
+                        .map(|packet| {
+                            let slot_start = size_of::<Signature>() + size_of::<ShredType>();
+                            let slot_end = slot_start + size_of::<u64>();
+                            if packet.meta.size < slot_end {
+                                return std::u64::MAX;
+                            }
+                            let slot: Option<u64> =
+                                deserialize(&packet.data[slot_start..slot_end]).ok();
+                            match slot {
+                                Some(slot) if slot_leaders.get(&slot).is_some() => slot,
+                                _ => std::u64::MAX,
+                            }
+                        })
+                        .collect()
+                })
+                .collect()
+        })
+    });
+    let mut keys_to_slots: HashMap<Pubkey, Vec<u64>> = HashMap::new();
+    for batch in slots.iter() {
+        for slot in batch.iter() {
+            let key = slot_leaders.get(slot).unwrap();
+            keys_to_slots
+                .entry(*key)
+                .or_insert_with(|| vec![])
+                .push(*slot);
+        }
+    }
+    let mut pubkeys: PinnedVec<Pubkey> = recycler_pubkeys.allocate("shred_gpu_pubkeys");
+    let mut slot_to_key_ix = HashMap::new();
+    for (i, (k, slots)) in keys_to_slots.iter().enumerate() {
+        pubkeys.push(*k);
+        for s in slots {
+            slot_to_key_ix.insert(s, i);
+        }
+    }
+    let mut offsets = recycler_offsets.allocate("shred_offsets");
+    slots.iter().for_each(|packet_slots| {
+        packet_slots.iter().for_each(|slot| {
+            offsets.push((slot_to_key_ix.get(slot).unwrap() * size_of::<Pubkey>()) as u32);
+        });
+    });
+    //HACK: Pubkeys vector is passed along as a `Packets` buffer to the GPU
+    //TODO: GPU needs a more opaque interface, which can handle variable sized structures for data
+    //Pad the Pubkeys buffer such that it is bigger than a buffer of Packet sized elems
+    let num_in_packets =
+        (pubkeys.len() * size_of::<Pubkey>() + (size_of::<Packet>() - 1)) / size_of::<Packet>();
+    trace!("num_in_packets {}", num_in_packets);
+    //number of bytes missing
+    let missing = num_in_packets * size_of::<Packet>() - pubkeys.len() * size_of::<Pubkey>();
+    trace!("missing {}", missing);
+    //extra Pubkeys needed to fill the buffer
+    let extra = (missing + size_of::<Pubkey>() - 1) / size_of::<Pubkey>();
+    trace!("extra {}", extra);
+    trace!("pubkeys {}", pubkeys.len());
+    for _ in 0..extra {
+        pubkeys.push(Pubkey::default());
+        trace!("pubkeys {}", pubkeys.len());
+    }
+    trace!("pubkeys {:?}", pubkeys);
+    trace!("offsets {:?}", offsets);
+    (pubkeys, offsets, num_in_packets)
+}
+
+fn shred_gpu_offsets(
+    mut pubkeys_end: u32,
+    batches: &[Packets],
+    recycler_offsets: &Recycler<TxOffset>,
+) -> (TxOffset, TxOffset, TxOffset, Vec<Vec<u32>>) {
+    let mut signature_offsets = recycler_offsets.allocate("shred_signatures");
+    let mut msg_start_offsets = recycler_offsets.allocate("shred_msg_starts");
+    let mut msg_sizes = recycler_offsets.allocate("shred_msg_sizes");
+    let mut v_sig_lens = vec![];
+    for batch in batches {
+        let mut sig_lens = Vec::new();
+        for packet in &batch.packets {
+            let sig_start = pubkeys_end;
+            let sig_end = sig_start + size_of::<Signature>() as u32;
+            let msg_start = sig_end;
+            let msg_end = sig_start + packet.meta.size as u32;
+            signature_offsets.push(sig_start);
+            msg_start_offsets.push(msg_start);
+            let msg_size = if msg_end < msg_start {
+                0
+            } else {
+                msg_end - msg_start
+            };
+            msg_sizes.push(msg_size);
+            sig_lens.push(1);
+            pubkeys_end += size_of::<Packet>() as u32;
+        }
+        v_sig_lens.push(sig_lens);
+    }
+    (signature_offsets, msg_start_offsets, msg_sizes, v_sig_lens)
+}
+
+pub fn verify_shreds_gpu(
+    batches: &[Packets],
+    slot_leaders: &HashMap<u64, Pubkey>,
+    recycler_offsets: &Recycler<TxOffset>,
+    recycler_pubkeys: &Recycler<PinnedVec<Pubkey>>,
+    recycler_out: &Recycler<PinnedVec<u8>>,
+) -> Vec<Vec<u8>> {
+    let api = perf_libs::api();
+    if api.is_none() {
+        return verify_shreds_cpu(batches, slot_leaders);
+    }
+    let api = api.unwrap();
+
+    let mut elems = Vec::new();
+    let mut rvs = Vec::new();
+    let count = sigverify::batch_size(batches);
+    let (pubkeys, pubkey_offsets, mut num_packets) =
+        shred_gpu_pubkeys(batches, slot_leaders, recycler_offsets, recycler_pubkeys);
+    //HACK: Pubkeys vector is passed along as a `Packets` buffer to the GPU
+    //TODO: GPU needs a more opaque interface, which can handle variable sized structures for data
+    let pubkeys_len = (num_packets * size_of::<Packet>()) as u32;
+    trace!("num_packets: {}", num_packets);
+    trace!("pubkeys_len: {}", pubkeys_len);
+    let (signature_offsets, msg_start_offsets, msg_sizes, v_sig_lens) =
+        shred_gpu_offsets(pubkeys_len, batches, recycler_offsets);
+    let mut out = recycler_out.allocate("out_buffer");
+    out.set_pinnable();
+    elems.push(
+        perf_libs::Elems {
+            #![allow(clippy::cast_ptr_alignment)]
+            elems: pubkeys.as_ptr() as *const solana_sdk::packet::Packet,
+            num: num_packets as u32,
+        },
+    );
+
+    for p in batches {
+        elems.push(perf_libs::Elems {
+            elems: p.packets.as_ptr(),
+            num: p.packets.len() as u32,
+        });
+        let mut v = Vec::new();
+        v.resize(p.packets.len(), 0);
+        rvs.push(v);
+        num_packets += p.packets.len();
+    }
+    out.resize(signature_offsets.len(), 0);
+
+    trace!("Starting verify num packets: {}", num_packets);
+    trace!("elem len: {}", elems.len() as u32);
+    trace!("packet sizeof: {}", size_of::<Packet>() as u32);
+    const USE_NON_DEFAULT_STREAM: u8 = 1;
+    unsafe {
+        let res = (api.ed25519_verify_many)(
+            elems.as_ptr(),
+            elems.len() as u32,
+            size_of::<Packet>() as u32,
+            num_packets as u32,
+            signature_offsets.len() as u32,
+            msg_sizes.as_ptr(),
+            pubkey_offsets.as_ptr(),
+            signature_offsets.as_ptr(),
+            msg_start_offsets.as_ptr(),
+            out.as_mut_ptr(),
+            USE_NON_DEFAULT_STREAM,
+        );
+        if res != 0 {
+            trace!("RETURN!!!: {}", res);
+        }
+    }
+    trace!("done verify");
+    trace!("out buf {:?}", out);
+
+    sigverify::copy_return_values(&v_sig_lens, &out, &mut rvs);
+
+    inc_new_counter_debug!("ed25519_shred_verify_gpu", count);
+    recycler_out.recycle(out);
+    recycler_offsets.recycle(signature_offsets);
+    recycler_offsets.recycle(pubkey_offsets);
+    recycler_offsets.recycle(msg_sizes);
+    recycler_offsets.recycle(msg_start_offsets);
+    recycler_pubkeys.recycle(pubkeys);
+    rvs
+}
+
+#[cfg(test)]
+pub mod tests {
+    use super::*;
+    use solana_ledger::shred::{Shred, Shredder};
+    use solana_sdk::signature::{Keypair, KeypairUtil};
+    #[test]
+    fn test_sigverify_shred_cpu() {
+        solana_logger::setup();
+        let mut packet = Packet::default();
+        let slot = 0xdeadc0de;
+        let mut shred = Shred::new_from_data(slot, 0xc0de, 0xdead, Some(&[1, 2, 3, 4]), true, true);
+        assert_eq!(shred.slot(), slot);
+        let keypair = Keypair::new();
+        Shredder::sign_shred(&keypair, &mut shred);
+        trace!("signature {}", shred.common_header.signature);
+        packet.data[0..shred.payload.len()].copy_from_slice(&shred.payload);
+        packet.meta.size = shred.payload.len();
+
+        let mut leader_slots: HashMap<u64, Pubkey> = HashMap::new();
+        leader_slots.insert(slot, keypair.pubkey());
+        let rv = verify_shred_cpu(&packet, &leader_slots);
+        assert_eq!(rv, Some(1));
+
+        let wrong_keypair = Keypair::new();
+        leader_slots.insert(slot, wrong_keypair.pubkey());
+        let rv = verify_shred_cpu(&packet, &leader_slots);
+        assert_eq!(rv, Some(0));
+
+        leader_slots.remove(&slot);
+        let rv = verify_shred_cpu(&packet, &leader_slots);
+        assert_eq!(rv, None);
+    }
+
+    #[test]
+    fn test_sigverify_shreds_cpu() {
+        solana_logger::setup();
+        let mut batch = [Packets::default()];
+        let slot = 0xdeadc0de;
+        let mut shred = Shred::new_from_data(slot, 0xc0de, 0xdead, Some(&[1, 2, 3, 4]), true, true);
+        let keypair = Keypair::new();
+        Shredder::sign_shred(&keypair, &mut shred);
+        batch[0].packets.resize(1, Packet::default());
+        batch[0].packets[0].data[0..shred.payload.len()].copy_from_slice(&shred.payload);
+        batch[0].packets[0].meta.size = shred.payload.len();
+
+        let mut leader_slots: HashMap<u64, Pubkey> = HashMap::new();
+        leader_slots.insert(slot, keypair.pubkey());
+        let rv = verify_shreds_cpu(&batch, &leader_slots);
+        assert_eq!(rv, vec![vec![1]]);
+
+        let wrong_keypair = Keypair::new();
+        leader_slots.insert(slot, wrong_keypair.pubkey());
+        let rv = verify_shreds_cpu(&batch, &leader_slots);
+        assert_eq!(rv, vec![vec![0]]);
+
+        leader_slots.remove(&slot);
+        let rv = verify_shreds_cpu(&batch, &leader_slots);
+        assert_eq!(rv, vec![vec![0]]);
+
+        leader_slots.insert(slot, keypair.pubkey());
+        batch[0].packets[0].meta.size = 0;
+        let rv = verify_shreds_cpu(&batch, &leader_slots);
+        assert_eq!(rv, vec![vec![0]]);
+    }
+
+    #[test]
+    fn test_sigverify_shreds_gpu() {
+        solana_logger::setup();
+        let recycler_offsets = Recycler::default();
+        let recycler_pubkeys = Recycler::default();
+        let recycler_out = Recycler::default();
+        let mut leader_slots: HashMap<u64, Pubkey> = HashMap::new();
+        leader_slots.insert(std::u64::MAX, Pubkey::default());
+
+        let mut batch = [Packets::default()];
+        let slot = 0xdeadc0de;
+        let mut shred = Shred::new_from_data(slot, 0xc0de, 0xdead, Some(&[1, 2, 3, 4]), true, true);
+        let keypair = Keypair::new();
+        Shredder::sign_shred(&keypair, &mut shred);
+        batch[0].packets.resize(1, Packet::default());
+        batch[0].packets[0].data[0..shred.payload.len()].copy_from_slice(&shred.payload);
+        batch[0].packets[0].meta.size = shred.payload.len();
+
+        leader_slots.insert(slot, keypair.pubkey());
+        let rv = verify_shreds_gpu(
+            &batch,
+            &leader_slots,
+            &recycler_offsets,
+            &recycler_pubkeys,
+            &recycler_out,
+        );
+        assert_eq!(rv, vec![vec![1]]);
+
+        let wrong_keypair = Keypair::new();
+        leader_slots.insert(slot, wrong_keypair.pubkey());
+        let rv = verify_shreds_gpu(
+            &batch,
+            &leader_slots,
+            &recycler_offsets,
+            &recycler_pubkeys,
+            &recycler_out,
+        );
+        assert_eq!(rv, vec![vec![0]]);
+
+        leader_slots.remove(&slot);
+        let rv = verify_shreds_gpu(
+            &batch,
+            &leader_slots,
+            &recycler_offsets,
+            &recycler_pubkeys,
+            &recycler_out,
+        );
+        assert_eq!(rv, vec![vec![0]]);
+
+        batch[0].packets[0].meta.size = 0;
+        leader_slots.insert(slot, keypair.pubkey());
+        let rv = verify_shreds_gpu(
+            &batch,
+            &leader_slots,
+            &recycler_offsets,
+            &recycler_pubkeys,
+            &recycler_out,
+        );
+        assert_eq!(rv, vec![vec![0]]);
+    }
+}
diff --git a/ledger/src/shred.rs b/ledger/src/shred.rs
index df3bfdaee..539200c07 100644
--- a/ledger/src/shred.rs
+++ b/ledger/src/shred.rs
@@ -442,7 +442,7 @@ impl Shredder {
         (data_shreds, coding_shreds, last_shred_index + 1)
     }
 
-    pub fn sign_shred(signer: &Arc<Keypair>, shred: &mut Shred) {
+    pub fn sign_shred(signer: &Keypair, shred: &mut Shred) {
         let signature = signer.sign_message(&shred.payload[SIZE_OF_SIGNATURE..]);
         bincode::serialize_into(&mut shred.payload[..SIZE_OF_SIGNATURE], &signature)
             .expect("Failed to generate serialized signature");