diff --git a/l1-contracts/src/core/sequencer_selection/Leonidas.sol b/l1-contracts/src/core/sequencer_selection/Leonidas.sol
index 8c646904b22..48cbaef0579 100644
--- a/l1-contracts/src/core/sequencer_selection/Leonidas.sol
+++ b/l1-contracts/src/core/sequencer_selection/Leonidas.sol
@@ -375,8 +375,7 @@ contract Leonidas is Ownable, ILeonidas {
     // Validate the attestations
     uint256 validAttestations = 0;
 
-    bytes32 ethSignedDigest = _digest.toEthSignedMessageHash();
-
+    bytes32 digest = _digest.toEthSignedMessageHash();
     for (uint256 i = 0; i < _signatures.length; i++) {
       SignatureLib.Signature memory signature = _signatures[i];
       if (signature.isEmpty) {
@@ -384,7 +383,7 @@ contract Leonidas is Ownable, ILeonidas {
       }
 
       // The verification will throw if invalid
-      signature.verify(committee[i], ethSignedDigest);
+      signature.verify(committee[i], digest);
       validAttestations++;
     }
 
diff --git a/l1-contracts/test/sparta/Sparta.t.sol b/l1-contracts/test/sparta/Sparta.t.sol
index f00adf2ea2d..3454245ffbf 100644
--- a/l1-contracts/test/sparta/Sparta.t.sol
+++ b/l1-contracts/test/sparta/Sparta.t.sol
@@ -7,7 +7,6 @@ import {DecoderBase} from "../decoders/Base.sol";
 import {DataStructures} from "../../src/core/libraries/DataStructures.sol";
 import {Constants} from "../../src/core/libraries/ConstantsGen.sol";
 import {SignatureLib} from "../../src/core/sequencer_selection/SignatureLib.sol";
-import {MessageHashUtils} from "@oz/utils/cryptography/MessageHashUtils.sol";
 
 import {Registry} from "../../src/core/messagebridge/Registry.sol";
 import {Inbox} from "../../src/core/messagebridge/Inbox.sol";
@@ -20,11 +19,12 @@ import {MerkleTestUtil} from "../merkle/TestUtil.sol";
 import {PortalERC20} from "../portals/PortalERC20.sol";
 import {TxsDecoderHelper} from "../decoders/helpers/TxsDecoderHelper.sol";
 import {IFeeJuicePortal} from "../../src/core/interfaces/IFeeJuicePortal.sol";
+import {MessageHashUtils} from "@oz/utils/cryptography/MessageHashUtils.sol";
+
 /**
  * We are using the same blocks as from Rollup.t.sol.
  * The tests in this file is testing the sequencer selection
  */
-
 contract SpartaTest is DecoderBase {
   using MessageHashUtils for bytes32;
 
@@ -283,8 +283,9 @@ contract SpartaTest is DecoderBase {
     returns (SignatureLib.Signature memory)
   {
     uint256 privateKey = privateKeys[_signer];
-    bytes32 digestForSig = _digest.toEthSignedMessageHash();
-    (uint8 v, bytes32 r, bytes32 s) = vm.sign(privateKey, digestForSig);
+
+    bytes32 digest = _digest.toEthSignedMessageHash();
+    (uint8 v, bytes32 r, bytes32 s) = vm.sign(privateKey, digest);
 
     return SignatureLib.Signature({isEmpty: false, v: v, r: r, s: s});
   }
diff --git a/yarn-project/archiver/src/archiver/eth_log_handlers.ts b/yarn-project/archiver/src/archiver/eth_log_handlers.ts
index fa218fb2086..5781f1a3d0f 100644
--- a/yarn-project/archiver/src/archiver/eth_log_handlers.ts
+++ b/yarn-project/archiver/src/archiver/eth_log_handlers.ts
@@ -1,6 +1,7 @@
-import { Body, InboxLeaf, L2Block, type ViemSignature } from '@aztec/circuit-types';
+import { Body, InboxLeaf, L2Block } from '@aztec/circuit-types';
 import { AppendOnlyTreeSnapshot, Header, Proof } from '@aztec/circuits.js';
 import { type EthAddress } from '@aztec/foundation/eth-address';
+import { type ViemSignature } from '@aztec/foundation/eth-signature';
 import { Fr } from '@aztec/foundation/fields';
 import { numToUInt32BE } from '@aztec/foundation/serialize';
 import { InboxAbi, RollupAbi } from '@aztec/l1-artifacts';
diff --git a/yarn-project/circuit-types/src/p2p/block_attestation.test.ts b/yarn-project/circuit-types/src/p2p/block_attestation.test.ts
index 1a0ba523548..9fe3789454b 100644
--- a/yarn-project/circuit-types/src/p2p/block_attestation.test.ts
+++ b/yarn-project/circuit-types/src/p2p/block_attestation.test.ts
@@ -3,8 +3,8 @@ import { BlockAttestation } from './block_attestation.js';
 import { makeBlockAttestation, randomSigner } from './mocks.js';
 
 describe('Block Attestation serialization / deserialization', () => {
-  it('Should serialize / deserialize', async () => {
-    const attestation = await makeBlockAttestation();
+  it('Should serialize / deserialize', () => {
+    const attestation = makeBlockAttestation();
 
     const serialized = attestation.toBuffer();
     const deserialized = BlockAttestation.fromBuffer(serialized);
@@ -12,17 +12,17 @@ describe('Block Attestation serialization / deserialization', () => {
     expect(deserialized).toEqual(attestation);
   });
 
-  it('Should serialize / deserialize + recover sender', async () => {
+  it('Should serialize / deserialize + recover sender', () => {
     const account = randomSigner();
 
-    const proposal = await makeBlockAttestation(account);
+    const proposal = makeBlockAttestation(account);
     const serialized = proposal.toBuffer();
     const deserialized = BlockAttestation.fromBuffer(serialized);
 
     expect(deserialized).toEqual(proposal);
 
     // Recover signature
-    const sender = await deserialized.getSender();
-    expect(sender.toChecksumString()).toEqual(account.address);
+    const sender = deserialized.getSender();
+    expect(sender).toEqual(account.address);
   });
 });
diff --git a/yarn-project/circuit-types/src/p2p/block_attestation.ts b/yarn-project/circuit-types/src/p2p/block_attestation.ts
index e38effdb368..ec554f45203 100644
--- a/yarn-project/circuit-types/src/p2p/block_attestation.ts
+++ b/yarn-project/circuit-types/src/p2p/block_attestation.ts
@@ -1,14 +1,13 @@
-import { EthAddress, Header } from '@aztec/circuits.js';
+import { type EthAddress, Header } from '@aztec/circuits.js';
 import { Buffer32 } from '@aztec/foundation/buffer';
+import { recoverAddress } from '@aztec/foundation/crypto';
+import { Signature } from '@aztec/foundation/eth-signature';
 import { Fr } from '@aztec/foundation/fields';
 import { BufferReader, serializeToBuffer } from '@aztec/foundation/serialize';
 
-import { recoverMessageAddress } from 'viem';
-
 import { TxHash } from '../tx/tx_hash.js';
-import { get0xStringHashedSignaturePayload, getSignaturePayload } from './block_utils.js';
+import { getHashedSignaturePayloadEthSignedMessage, getSignaturePayload } from './block_utils.js';
 import { Gossipable } from './gossipable.js';
-import { Signature } from './signature.js';
 import { TopicType, createTopicString } from './topic_type.js';
 
 export class BlockAttestationHash extends Buffer32 {
@@ -53,16 +52,12 @@ export class BlockAttestation extends Gossipable {
    * Lazily evaluate and cache the sender of the attestation
    * @returns The sender of the attestation
    */
-  async getSender() {
+  getSender() {
     if (!this.sender) {
       // Recover the sender from the attestation
-      const hashed = get0xStringHashedSignaturePayload(this.archive, this.txHashes);
-      const address = await recoverMessageAddress({
-        message: { raw: hashed },
-        signature: this.signature.to0xString(),
-      });
+      const hashed = getHashedSignaturePayloadEthSignedMessage(this.archive, this.txHashes);
       // Cache the sender for later use
-      this.sender = EthAddress.fromString(address);
+      this.sender = recoverAddress(hashed, this.signature);
     }
 
     return this.sender;
diff --git a/yarn-project/circuit-types/src/p2p/block_proposal.test.ts b/yarn-project/circuit-types/src/p2p/block_proposal.test.ts
index 6eb1c427f4f..d6c91f14b20 100644
--- a/yarn-project/circuit-types/src/p2p/block_proposal.test.ts
+++ b/yarn-project/circuit-types/src/p2p/block_proposal.test.ts
@@ -3,8 +3,8 @@ import { BlockProposal } from './block_proposal.js';
 import { makeBlockProposal, randomSigner } from './mocks.js';
 
 describe('Block Proposal serialization / deserialization', () => {
-  it('Should serialize / deserialize', async () => {
-    const proposal = await makeBlockProposal();
+  it('Should serialize / deserialize', () => {
+    const proposal = makeBlockProposal();
 
     const serialized = proposal.toBuffer();
     const deserialized = BlockProposal.fromBuffer(serialized);
@@ -12,17 +12,17 @@ describe('Block Proposal serialization / deserialization', () => {
     expect(deserialized).toEqual(proposal);
   });
 
-  it('Should serialize / deserialize + recover sender', async () => {
+  it('Should serialize / deserialize + recover sender', () => {
     const account = randomSigner();
 
-    const proposal = await makeBlockProposal(account);
+    const proposal = makeBlockProposal(account);
     const serialized = proposal.toBuffer();
     const deserialized = BlockProposal.fromBuffer(serialized);
 
     expect(deserialized).toEqual(proposal);
 
     // Recover signature
-    const sender = await deserialized.getSender();
-    expect(sender.toChecksumString()).toEqual(account.address);
+    const sender = deserialized.getSender();
+    expect(sender).toEqual(account.address);
   });
 });
diff --git a/yarn-project/circuit-types/src/p2p/block_proposal.ts b/yarn-project/circuit-types/src/p2p/block_proposal.ts
index 8164e755117..7da744c377a 100644
--- a/yarn-project/circuit-types/src/p2p/block_proposal.ts
+++ b/yarn-project/circuit-types/src/p2p/block_proposal.ts
@@ -1,14 +1,17 @@
-import { EthAddress, Header } from '@aztec/circuits.js';
+import { type EthAddress, Header } from '@aztec/circuits.js';
 import { Buffer32 } from '@aztec/foundation/buffer';
+import { recoverAddress } from '@aztec/foundation/crypto';
+import { Signature } from '@aztec/foundation/eth-signature';
 import { Fr } from '@aztec/foundation/fields';
 import { BufferReader, serializeToBuffer } from '@aztec/foundation/serialize';
 
-import { recoverMessageAddress } from 'viem';
-
 import { TxHash } from '../tx/tx_hash.js';
-import { get0xStringHashedSignaturePayload, getHashedSignaturePayload, getSignaturePayload } from './block_utils.js';
+import {
+  getHashedSignaturePayload,
+  getHashedSignaturePayloadEthSignedMessage,
+  getSignaturePayload,
+} from './block_utils.js';
 import { Gossipable } from './gossipable.js';
-import { Signature } from './signature.js';
 import { TopicType, createTopicString } from './topic_type.js';
 
 export class BlockProposalHash extends Buffer32 {
@@ -54,7 +57,7 @@ export class BlockProposal extends Gossipable {
     header: Header,
     archive: Fr,
     txs: TxHash[],
-    payloadSigner: (payload: Buffer) => Promise<Signature>,
+    payloadSigner: (payload: Buffer32) => Promise<Signature>,
   ) {
     const hashed = getHashedSignaturePayload(archive, txs);
     const sig = await payloadSigner(hashed);
@@ -65,16 +68,11 @@ export class BlockProposal extends Gossipable {
   /**Get Sender
    * Lazily evaluate the sender of the proposal; result is cached
    */
-  async getSender() {
+  getSender() {
     if (!this.sender) {
-      // performance note(): this signature method requires another hash behind the scenes
-      const hashed = get0xStringHashedSignaturePayload(this.archive, this.txs);
-      const address = await recoverMessageAddress({
-        message: { raw: hashed },
-        signature: this.signature.to0xString(),
-      });
+      const hashed = getHashedSignaturePayloadEthSignedMessage(this.archive, this.txs);
       // Cache the sender for later use
-      this.sender = EthAddress.fromString(address);
+      this.sender = recoverAddress(hashed, this.signature);
     }
 
     return this.sender;
diff --git a/yarn-project/circuit-types/src/p2p/block_utils.ts b/yarn-project/circuit-types/src/p2p/block_utils.ts
index cd1c5a48842..d4f4cfc34b7 100644
--- a/yarn-project/circuit-types/src/p2p/block_utils.ts
+++ b/yarn-project/circuit-types/src/p2p/block_utils.ts
@@ -1,7 +1,8 @@
-import { keccak256 as keccak256Buffer } from '@aztec/foundation/crypto';
+import { Buffer32 } from '@aztec/foundation/buffer';
+import { keccak256, makeEthSignDigest } from '@aztec/foundation/crypto';
 import { type Fr } from '@aztec/foundation/fields';
 
-import { encodeAbiParameters, keccak256 as keccak2560xString, parseAbiParameters } from 'viem';
+import { encodeAbiParameters, parseAbiParameters } from 'viem';
 
 import { type TxHash } from '../tx/tx_hash.js';
 
@@ -25,10 +26,17 @@ export function getSignaturePayload(archive: Fr, txs: TxHash[]) {
  * @param txs - The transactions in the block
  * @returns The hashed payload for the signature of the block proposal
  */
-export function getHashedSignaturePayload(archive: Fr, txs: TxHash[]): Buffer {
-  return keccak256Buffer(getSignaturePayload(archive, txs));
+export function getHashedSignaturePayload(archive: Fr, txs: TxHash[]): Buffer32 {
+  return Buffer32.fromBuffer(keccak256(getSignaturePayload(archive, txs)));
 }
 
-export function get0xStringHashedSignaturePayload(archive: Fr, txs: TxHash[]): `0x${string}` {
-  return keccak2560xString(getSignaturePayload(archive, txs));
+/**
+ * Get the hashed payload for the signature of the block proposal as an Ethereum signed message EIP-712
+ * @param archive - The archive of the block
+ * @param txs - The transactions in the block
+ * @returns The hashed payload for the signature of the block proposal as an Ethereum signed message
+ */
+export function getHashedSignaturePayloadEthSignedMessage(archive: Fr, txs: TxHash[]): Buffer32 {
+  const payload = getHashedSignaturePayload(archive, txs);
+  return makeEthSignDigest(payload);
 }
diff --git a/yarn-project/circuit-types/src/p2p/index.ts b/yarn-project/circuit-types/src/p2p/index.ts
index e6c268523c1..8afa13bb6c5 100644
--- a/yarn-project/circuit-types/src/p2p/index.ts
+++ b/yarn-project/circuit-types/src/p2p/index.ts
@@ -3,5 +3,4 @@ export * from './block_proposal.js';
 export * from './interface.js';
 export * from './gossipable.js';
 export * from './topic_type.js';
-export * from './signature.js';
 export * from './block_utils.js';
diff --git a/yarn-project/circuit-types/src/p2p/mocks.ts b/yarn-project/circuit-types/src/p2p/mocks.ts
index 2e4b9495d66..f211a6fc523 100644
--- a/yarn-project/circuit-types/src/p2p/mocks.ts
+++ b/yarn-project/circuit-types/src/p2p/mocks.ts
@@ -1,41 +1,39 @@
 import { makeHeader } from '@aztec/circuits.js/testing';
+import { Buffer32 } from '@aztec/foundation/buffer';
+import { Secp256k1Signer } from '@aztec/foundation/crypto';
 import { Fr } from '@aztec/foundation/fields';
 
-import { type PrivateKeyAccount } from 'viem';
-import { generatePrivateKey, privateKeyToAccount } from 'viem/accounts';
-
 import { TxHash } from '../tx/tx_hash.js';
 import { BlockAttestation } from './block_attestation.js';
 import { BlockProposal } from './block_proposal.js';
-import { get0xStringHashedSignaturePayload } from './block_utils.js';
-import { Signature } from './signature.js';
+import { getHashedSignaturePayloadEthSignedMessage } from './block_utils.js';
 
-export const makeBlockProposal = async (signer?: PrivateKeyAccount): Promise<BlockProposal> => {
+export const makeBlockProposal = (signer?: Secp256k1Signer): BlockProposal => {
   signer = signer || randomSigner();
 
   const blockHeader = makeHeader(1);
   const archive = Fr.random();
   const txs = [0, 1, 2, 3, 4, 5].map(() => TxHash.random());
-  const hash = get0xStringHashedSignaturePayload(archive, txs);
-  const signature = Signature.from0xString(await signer.signMessage({ message: { raw: hash } }));
+  const hash = getHashedSignaturePayloadEthSignedMessage(archive, txs);
+  const signature = signer.sign(hash);
 
   return new BlockProposal(blockHeader, archive, txs, signature);
 };
 
 // TODO(https://github.com/AztecProtocol/aztec-packages/issues/8028)
-export const makeBlockAttestation = async (signer?: PrivateKeyAccount): Promise<BlockAttestation> => {
+export const makeBlockAttestation = (signer?: Secp256k1Signer): BlockAttestation => {
   signer = signer || randomSigner();
 
   const blockHeader = makeHeader(1);
   const archive = Fr.random();
   const txs = [0, 1, 2, 3, 4, 5].map(() => TxHash.random());
-  const hash = get0xStringHashedSignaturePayload(archive, txs);
-  const signature = Signature.from0xString(await signer.signMessage({ message: { raw: hash } }));
+  const hash = getHashedSignaturePayloadEthSignedMessage(archive, txs);
+  const signature = signer.sign(hash);
 
   return new BlockAttestation(blockHeader, archive, txs, signature);
 };
 
-export const randomSigner = (): PrivateKeyAccount => {
-  const privateKey = generatePrivateKey();
-  return privateKeyToAccount(privateKey);
+export const randomSigner = (): Secp256k1Signer => {
+  const privateKey = Buffer32.random();
+  return new Secp256k1Signer(privateKey);
 };
diff --git a/yarn-project/circuit-types/src/p2p/signature.test.ts b/yarn-project/circuit-types/src/p2p/signature.test.ts
deleted file mode 100644
index 7e443a4f105..00000000000
--- a/yarn-project/circuit-types/src/p2p/signature.test.ts
+++ /dev/null
@@ -1,31 +0,0 @@
-import { Fr } from '@aztec/foundation/fields';
-
-import { recoverMessageAddress } from 'viem';
-
-import { randomSigner } from './mocks.js';
-import { Signature } from './signature.js';
-
-describe('Signature serialization / deserialization', () => {
-  it('Should serialize / deserialize', async () => {
-    const signer = randomSigner();
-
-    const originalMessage = Fr.random();
-    const m = `0x${originalMessage.toBuffer().toString('hex')}`;
-
-    const signature = await signer.signMessage({ message: m });
-
-    const signatureObj = Signature.from0xString(signature);
-
-    // Serde
-    const serialized = signatureObj.toBuffer();
-    const deserialized = Signature.fromBuffer(serialized);
-    expect(deserialized).toEqual(signatureObj);
-
-    const as0x = deserialized.to0xString();
-    expect(as0x).toEqual(signature);
-
-    // Recover signature
-    const sender = await recoverMessageAddress({ message: originalMessage.toString(), signature: as0x });
-    expect(sender).toEqual(signer.address);
-  });
-});
diff --git a/yarn-project/foundation/package.json b/yarn-project/foundation/package.json
index f14bc84c6e1..2af937f8c18 100644
--- a/yarn-project/foundation/package.json
+++ b/yarn-project/foundation/package.json
@@ -17,6 +17,7 @@
     "./crypto": "./dest/crypto/index.js",
     "./error": "./dest/error/index.js",
     "./eth-address": "./dest/eth-address/index.js",
+    "./eth-signature": "./dest/eth-signature/index.js",
     "./queue": "./dest/queue/index.js",
     "./fs": "./dest/fs/index.js",
     "./buffer": "./dest/buffer/index.js",
@@ -144,7 +145,8 @@
     "prettier": "^2.7.1",
     "supertest": "^6.3.3",
     "ts-node": "^10.9.1",
-    "typescript": "^5.0.4"
+    "typescript": "^5.0.4",
+    "viem": "^2.7.15"
   },
   "files": [
     "dest",
diff --git a/yarn-project/foundation/src/buffer/buffer32.ts b/yarn-project/foundation/src/buffer/buffer32.ts
index 736c0ada457..a3a1d6b6702 100644
--- a/yarn-project/foundation/src/buffer/buffer32.ts
+++ b/yarn-project/foundation/src/buffer/buffer32.ts
@@ -112,7 +112,25 @@ export class Buffer32 {
    * @param str - The TX hash in string format.
    * @returns A new Buffer32 object.
    */
+  public static fromStringUnchecked(str: string): Buffer32 {
+    return new Buffer32(Buffer.from(str, 'hex'));
+  }
+
+  /**
+   * Converts a string into a Buffer32 object.
+   * NOTE: this method includes checks for the 0x prefix and the length of the string.
+   *       if you dont need this checks, use fromStringUnchecked instead.
+   *
+   * @param str - The TX hash in string format.
+   * @returns A new Buffer32 object.
+   */
   public static fromString(str: string): Buffer32 {
+    if (str.startsWith('0x')) {
+      str = str.slice(2);
+    }
+    if (str.length !== 64) {
+      throw new Error(`Expected string to be 64 characters long, but was ${str.length}`);
+    }
     return new Buffer32(Buffer.from(str, 'hex'));
   }
 
diff --git a/yarn-project/foundation/src/crypto/index.ts b/yarn-project/foundation/src/crypto/index.ts
index 96365958e92..4a93708f498 100644
--- a/yarn-project/foundation/src/crypto/index.ts
+++ b/yarn-project/foundation/src/crypto/index.ts
@@ -6,6 +6,7 @@ export * from './sha256/index.js';
 export * from './sha512/index.js';
 export * from './pedersen/index.js';
 export * from './poseidon/index.js';
+export * from './secp256k1-signer/index.js';
 
 /**
  * Init the bb singleton. This constructs (if not already) the barretenberg sync api within bb.js itself.
diff --git a/yarn-project/foundation/src/crypto/secp256k1-signer/index.ts b/yarn-project/foundation/src/crypto/secp256k1-signer/index.ts
new file mode 100644
index 00000000000..b64273685d2
--- /dev/null
+++ b/yarn-project/foundation/src/crypto/secp256k1-signer/index.ts
@@ -0,0 +1,2 @@
+export * from './secp256k1_signer.js';
+export * from './utils.js';
diff --git a/yarn-project/foundation/src/crypto/secp256k1-signer/secp256k1_signer.test.ts b/yarn-project/foundation/src/crypto/secp256k1-signer/secp256k1_signer.test.ts
new file mode 100644
index 00000000000..707227208f2
--- /dev/null
+++ b/yarn-project/foundation/src/crypto/secp256k1-signer/secp256k1_signer.test.ts
@@ -0,0 +1,63 @@
+import { Buffer32 } from '@aztec/foundation/buffer';
+import { EthAddress } from '@aztec/foundation/eth-address';
+import { Signature } from '@aztec/foundation/eth-signature';
+
+import { hashMessage, recoverAddress as viemRecoverAddress, recoverPublicKey as viemRecoverPublicKey } from 'viem';
+import { type PrivateKeyAccount, generatePrivateKey, privateKeyToAccount, publicKeyToAddress } from 'viem/accounts';
+
+import { Secp256k1Signer } from './secp256k1_signer.js';
+import { recoverAddress as lightRecoverAddress, recoverPublicKey as lightRecoverPublicKey } from './utils.js';
+
+/**
+ * Differential fuzzing implementation of viem's signer and the secp256k1 signer
+ */
+describe('Secp256k1Signer', () => {
+  let viemSigner: PrivateKeyAccount;
+  let lightSigner: Secp256k1Signer;
+
+  beforeEach(() => {
+    const privateKey = generatePrivateKey();
+    viemSigner = privateKeyToAccount(privateKey);
+
+    lightSigner = new Secp256k1Signer(Buffer32.fromBuffer(Buffer.from(privateKey.slice(2), 'hex')));
+  });
+
+  it('Compare implementation against viem', async () => {
+    const message = Buffer.from('0x0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef', 'hex');
+    // Use to compare addresses at the end
+    const accountAddress = viemSigner.address;
+
+    // We use eth hashed message as viem will automatically do this with signMessage
+    const ethHashedMessage = hashMessage({ raw: message });
+    const ethHashedMessageBuffer = Buffer32.fromBuffer(Buffer.from(ethHashedMessage.slice(2), 'hex'));
+
+    const viemSignature = Signature.from0xString(await viemSigner.signMessage({ message: { raw: message } }));
+    const lightSignature = lightSigner.sign(ethHashedMessageBuffer);
+
+    // Check signatures match
+    expect(viemSignature.equals(lightSignature)).toBe(true);
+
+    const viemPublicKey = await viemRecoverPublicKey({ hash: ethHashedMessage, signature: viemSignature.to0xString() });
+    const lightPublicKey = lightRecoverPublicKey(ethHashedMessageBuffer, lightSignature);
+
+    // Check recovered public keys match
+    expect(Buffer.from(viemPublicKey.slice(2), 'hex')).toEqual(lightPublicKey);
+
+    // Get the eth address can be recovered from the message and signature
+    const viemPublicKeyToAddress = publicKeyToAddress(viemPublicKey);
+    const viemAddress = EthAddress.fromString(
+      await viemRecoverAddress({ hash: ethHashedMessage, signature: viemSignature.to0xString() }),
+    );
+    const lightAddress = lightRecoverAddress(
+      Buffer32.fromBuffer(Buffer.from(ethHashedMessage.slice(2), 'hex')),
+      lightSignature,
+    );
+
+    // Check viem signer matches
+    expect(viemAddress.toString()).toEqual(accountAddress.toString().toLowerCase());
+    expect(accountAddress.toString()).toEqual(viemPublicKeyToAddress.toString());
+
+    // Check light signer matches
+    expect(viemAddress.toString()).toEqual(lightAddress.toString());
+  });
+});
diff --git a/yarn-project/foundation/src/crypto/secp256k1-signer/secp256k1_signer.ts b/yarn-project/foundation/src/crypto/secp256k1-signer/secp256k1_signer.ts
new file mode 100644
index 00000000000..1af00bc4026
--- /dev/null
+++ b/yarn-project/foundation/src/crypto/secp256k1-signer/secp256k1_signer.ts
@@ -0,0 +1,34 @@
+import { type Buffer32 } from '@aztec/foundation/buffer';
+import { type EthAddress } from '@aztec/foundation/eth-address';
+import { type Signature } from '@aztec/foundation/eth-signature';
+
+import { addressFromPrivateKey, makeEthSignDigest, signMessage } from './utils.js';
+
+/**
+ * Secp256k1Signer
+ *
+ * A class for signing messages using a secp256k1 private key.
+ * - This is a slim drop in replacement for an Ethereum signer, so it can be used in the same way.
+ * - See `utils.ts` for functions that enable recovering addresses and public keys from signatures.
+ */
+export class Secp256k1Signer {
+  public readonly address: EthAddress;
+
+  constructor(private privateKey: Buffer32) {
+    this.address = addressFromPrivateKey(privateKey.buffer);
+  }
+
+  sign(message: Buffer32): Signature {
+    return signMessage(message, this.privateKey.buffer);
+  }
+
+  /**
+   * Sign a message using the same method as eth_sign
+   * @param message - The message to sign.
+   * @returns The signature.
+   */
+  signMessage(message: Buffer32): Signature {
+    const digest = makeEthSignDigest(message);
+    return this.sign(digest);
+  }
+}
diff --git a/yarn-project/foundation/src/crypto/secp256k1-signer/utils.ts b/yarn-project/foundation/src/crypto/secp256k1-signer/utils.ts
new file mode 100644
index 00000000000..c3be5e04b3a
--- /dev/null
+++ b/yarn-project/foundation/src/crypto/secp256k1-signer/utils.ts
@@ -0,0 +1,99 @@
+import { secp256k1 } from '@noble/curves/secp256k1';
+
+import { Buffer32 } from '../../buffer/buffer32.js';
+import { EthAddress } from '../../eth-address/index.js';
+import { Signature } from '../../eth-signature/eth_signature.js';
+import { keccak256 } from '../keccak/index.js';
+
+const ETH_SIGN_PREFIX = '\x19Ethereum Signed Message:\n32';
+
+// We just hash the message to make it easier to work with in the smart contract.
+export function makeEthSignDigest(message: Buffer32): Buffer32 {
+  const prefix = Buffer.from(ETH_SIGN_PREFIX);
+  return Buffer32.fromBuffer(keccak256(Buffer.concat([prefix, message.buffer])));
+}
+
+/**
+ * Converts a public key to an address.
+ * @param publicKey - The public key to convert.
+ * @returns The address.
+ */
+function publicKeyToAddress(publicKey: Buffer): EthAddress {
+  const hash = keccak256(publicKey.subarray(1));
+  return new EthAddress(hash.subarray(12));
+}
+
+/**
+ * Converts a private key to a public key.
+ * @param privateKey - The private key to convert.
+ * @returns The public key.
+ */
+export function publicKeyFromPrivateKey(privateKey: Buffer): Buffer {
+  return Buffer.from(secp256k1.getPublicKey(privateKey, false));
+}
+
+/**
+ * Converts a private key to an address.
+ * @param privateKey - The private key to convert.
+ * @returns The address.
+ */
+export function addressFromPrivateKey(privateKey: Buffer): EthAddress {
+  const publicKey = publicKeyFromPrivateKey(privateKey);
+  return publicKeyToAddress(publicKey);
+}
+
+/**
+ * Recovers an address from a hash and a signature.
+ * @param hash - The hash to recover the address from.
+ * @param signature - The signature to recover the address from.
+ * @returns The address.
+ */
+export function recoverAddress(hash: Buffer32, signature: Signature): EthAddress {
+  const publicKey = recoverPublicKey(hash, signature);
+  return publicKeyToAddress(publicKey);
+}
+
+/**
+ * @attribution - viem
+ * Converts a yParityOrV value to a recovery bit.
+ * @param yParityOrV - The yParityOrV value to convert.
+ * @returns The recovery bit.
+ */
+function toRecoveryBit(yParityOrV: number) {
+  if (yParityOrV === 0 || yParityOrV === 1) {
+    return yParityOrV;
+  }
+  if (yParityOrV === 27) {
+    return 0;
+  }
+  if (yParityOrV === 28) {
+    return 1;
+  }
+  throw new Error('Invalid yParityOrV value');
+}
+
+/**
+ * Signs a message using ecdsa over the secp256k1 curve.
+ * @param message - The message to sign.
+ * @param privateKey - The private key to sign the message with.
+ * @returns The signature.
+ */
+export function signMessage(message: Buffer32, privateKey: Buffer) {
+  const { r, s, recovery } = secp256k1.sign(message.buffer, privateKey);
+  return new Signature(Buffer32.fromBigInt(r), Buffer32.fromBigInt(s), recovery ? 28 : 27);
+}
+
+/**
+ * Recovers a public key from a hash and a signature.
+ * @param hash - The hash to recover the public key from.
+ * @param signature - The signature to recover the public key from.
+ * @returns The public key.
+ */
+export function recoverPublicKey(hash: Buffer32, signature: Signature): Buffer {
+  const { r, s, v } = signature;
+  const recoveryBit = toRecoveryBit(v);
+  const sig = new secp256k1.Signature(r.toBigInt(), s.toBigInt()).addRecoveryBit(recoveryBit);
+
+  const publicKey = sig.recoverPublicKey(hash.buffer).toHex(false);
+  return Buffer.from(publicKey, 'hex');
+}
diff --git a/yarn-project/foundation/src/eth-signature/eth_signature.test.ts b/yarn-project/foundation/src/eth-signature/eth_signature.test.ts
new file mode 100644
index 00000000000..d8fc489a675
--- /dev/null
+++ b/yarn-project/foundation/src/eth-signature/eth_signature.test.ts
@@ -0,0 +1,30 @@
+import { Buffer32 } from '@aztec/foundation/buffer';
+import { Secp256k1Signer, recoverAddress } from '@aztec/foundation/crypto';
+import { Fr } from '@aztec/foundation/fields';
+
+import { Signature } from './eth_signature.js';
+
+const randomSigner = () => {
+  const pk = Buffer32.random();
+  return new Secp256k1Signer(pk);
+};
+
+describe('Signature serialization / deserialization', () => {
+  it('Should serialize / deserialize', () => {
+    const signer = randomSigner();
+
+    const originalMessage = Fr.random();
+    const message = Buffer32.fromField(originalMessage);
+
+    const signature = signer.sign(message);
+
+    // Serde
+    const serialized = signature.toBuffer();
+    const deserialized = Signature.fromBuffer(serialized);
+    expect(deserialized).toEqual(signature);
+
+    // Recover signature
+    const sender = recoverAddress(message, signature);
+    expect(sender).toEqual(signer.address);
+  });
+});
diff --git a/yarn-project/circuit-types/src/p2p/signature.ts b/yarn-project/foundation/src/eth-signature/eth_signature.ts
similarity index 93%
rename from yarn-project/circuit-types/src/p2p/signature.ts
rename to yarn-project/foundation/src/eth-signature/eth_signature.ts
index 41870e59c62..2808ea63ce3 100644
--- a/yarn-project/circuit-types/src/p2p/signature.ts
+++ b/yarn-project/foundation/src/eth-signature/eth_signature.ts
@@ -32,6 +32,7 @@ export class Signature {
 
   static fromBuffer(buf: Buffer | BufferReader): Signature {
     const reader = BufferReader.asReader(buf);
+
     const r = reader.readObject(Buffer32);
     const s = reader.readObject(Buffer32);
     const v = reader.readNumber();
@@ -41,18 +42,6 @@ export class Signature {
     return new Signature(r, s, v, isEmpty);
   }
 
-  toBuffer(): Buffer {
-    return serializeToBuffer([this.r, this.s, this.v]);
-  }
-
-  static empty(): Signature {
-    return new Signature(Buffer32.ZERO, Buffer32.ZERO, 0, true);
-  }
-
-  to0xString(): `0x${string}` {
-    return `0x${this.r.toString()}${this.s.toString()}${this.v.toString(16)}`;
-  }
-
   /**
    * A seperate method exists for this as when signing locally with viem, as when
    * parsing from viem, we can expect the v value to be a u8, rather than our
@@ -71,6 +60,22 @@ export class Signature {
     return new Signature(r, s, v, isEmpty);
   }
 
+  static empty(): Signature {
+    return new Signature(Buffer32.ZERO, Buffer32.ZERO, 0, true);
+  }
+
+  equals(other: Signature): boolean {
+    return this.r.equals(other.r) && this.s.equals(other.s) && this.v === other.v && this.isEmpty === other.isEmpty;
+  }
+
+  toBuffer(): Buffer {
+    return serializeToBuffer([this.r, this.s, this.v]);
+  }
+
+  to0xString(): `0x${string}` {
+    return `0x${this.r.toString()}${this.s.toString()}${this.v.toString(16)}`;
+  }
+
   /**
    * Return the signature with `0x${string}` encodings for r and s
    */
diff --git a/yarn-project/foundation/src/eth-signature/index.ts b/yarn-project/foundation/src/eth-signature/index.ts
new file mode 100644
index 00000000000..73bc59dbe1a
--- /dev/null
+++ b/yarn-project/foundation/src/eth-signature/index.ts
@@ -0,0 +1 @@
+export * from './eth_signature.js';
diff --git a/yarn-project/foundation/src/fields/point.ts b/yarn-project/foundation/src/fields/point.ts
index 458252bd87a..3f3620f9348 100644
--- a/yarn-project/foundation/src/fields/point.ts
+++ b/yarn-project/foundation/src/fields/point.ts
@@ -1,5 +1,6 @@
 import { toBigIntBE } from '../bigint-buffer/index.js';
-import { poseidon2Hash, randomBoolean } from '../crypto/index.js';
+import { poseidon2Hash } from '../crypto/poseidon/index.js';
+import { randomBoolean } from '../crypto/random/index.js';
 import { BufferReader, FieldReader, serializeToBuffer } from '../serialize/index.js';
 import { Fr } from './fields.js';
 
diff --git a/yarn-project/foundation/src/index.ts b/yarn-project/foundation/src/index.ts
index 7a899eba520..78694f262f8 100644
--- a/yarn-project/foundation/src/index.ts
+++ b/yarn-project/foundation/src/index.ts
@@ -30,3 +30,4 @@ export * as worker from './worker/index.js';
 export * as testing from './testing/index.js';
 export * as config from './config/index.js';
 export * as buffer from './buffer/index.js';
+export * as ethSignature from './eth-signature/index.js';
diff --git a/yarn-project/p2p/src/attestation_pool/memory_attestation_pool.ts b/yarn-project/p2p/src/attestation_pool/memory_attestation_pool.ts
index 524a399aece..967429825da 100644
--- a/yarn-project/p2p/src/attestation_pool/memory_attestation_pool.ts
+++ b/yarn-project/p2p/src/attestation_pool/memory_attestation_pool.ts
@@ -19,18 +19,19 @@ export class InMemoryAttestationPool implements AttestationPool {
     }
   }
 
-  public async addAttestations(attestations: BlockAttestation[]): Promise<void> {
+  public addAttestations(attestations: BlockAttestation[]): Promise<void> {
     for (const attestation of attestations) {
       // Perf: order and group by slot before insertion
       const slotNumber = attestation.header.globalVariables.slotNumber;
 
-      const address = await attestation.getSender();
+      const address = attestation.getSender();
 
       const slotAttestationMap = getSlotOrDefault(this.attestations, slotNumber.toBigInt());
       slotAttestationMap.set(address.toString(), attestation);
 
       this.log.verbose(`Added attestation for slot ${slotNumber} from ${address}`);
     }
+    return Promise.resolve();
   }
 
   public deleteAttestationsForSlot(slot: bigint): Promise<void> {
@@ -40,12 +41,12 @@ export class InMemoryAttestationPool implements AttestationPool {
     return Promise.resolve();
   }
 
-  public async deleteAttestations(attestations: BlockAttestation[]): Promise<void> {
+  public deleteAttestations(attestations: BlockAttestation[]): Promise<void> {
     for (const attestation of attestations) {
       const slotNumber = attestation.header.globalVariables.slotNumber;
       const slotAttestationMap = this.attestations.get(slotNumber.toBigInt());
       if (slotAttestationMap) {
-        const address = await attestation.getSender();
+        const address = attestation.getSender();
         slotAttestationMap.delete(address.toString());
         this.log.verbose(`Deleted attestation for slot ${slotNumber} from ${address}`);
       }
diff --git a/yarn-project/p2p/src/attestation_pool/mocks.ts b/yarn-project/p2p/src/attestation_pool/mocks.ts
index 00194d52b96..7b2e55a7af6 100644
--- a/yarn-project/p2p/src/attestation_pool/mocks.ts
+++ b/yarn-project/p2p/src/attestation_pool/mocks.ts
@@ -1,5 +1,6 @@
-import { BlockAttestation, Signature, TxHash } from '@aztec/circuit-types';
+import { BlockAttestation, TxHash } from '@aztec/circuit-types';
 import { makeHeader } from '@aztec/circuits.js/testing';
+import { Signature } from '@aztec/foundation/eth-signature';
 import { Fr } from '@aztec/foundation/fields';
 import { serializeToBuffer } from '@aztec/foundation/serialize';
 
diff --git a/yarn-project/sequencer-client/src/client/sequencer-client.ts b/yarn-project/sequencer-client/src/client/sequencer-client.ts
index a6c95b16a7d..4ab745fc920 100644
--- a/yarn-project/sequencer-client/src/client/sequencer-client.ts
+++ b/yarn-project/sequencer-client/src/client/sequencer-client.ts
@@ -1,4 +1,5 @@
 import { type L1ToL2MessageSource, type L2BlockSource, type WorldStateSynchronizer } from '@aztec/circuit-types';
+import { type EthAddress } from '@aztec/foundation/eth-address';
 import { type P2P } from '@aztec/p2p';
 import { PublicProcessorFactory, type SimulationProvider } from '@aztec/simulator';
 import { type TelemetryClient } from '@aztec/telemetry-client';
@@ -99,7 +100,7 @@ export class SequencerClient {
     this.sequencer.restart();
   }
 
-  get coinbase() {
+  get coinbase(): EthAddress {
     return this.sequencer.coinbase;
   }
 
diff --git a/yarn-project/sequencer-client/src/publisher/l1-publisher.test.ts b/yarn-project/sequencer-client/src/publisher/l1-publisher.test.ts
index 0d09e221cd0..a3e6d007c42 100644
--- a/yarn-project/sequencer-client/src/publisher/l1-publisher.test.ts
+++ b/yarn-project/sequencer-client/src/publisher/l1-publisher.test.ts
@@ -1,5 +1,6 @@
-import { L2Block, type ViemSignature } from '@aztec/circuit-types';
+import { L2Block } from '@aztec/circuit-types';
 import { EthAddress } from '@aztec/circuits.js';
+import { type ViemSignature } from '@aztec/foundation/eth-signature';
 import { sleep } from '@aztec/foundation/sleep';
 import { RollupAbi } from '@aztec/l1-artifacts';
 import { NoopTelemetryClient } from '@aztec/telemetry-client/noop';
diff --git a/yarn-project/sequencer-client/src/publisher/l1-publisher.ts b/yarn-project/sequencer-client/src/publisher/l1-publisher.ts
index 0fbeb91f881..d7d5fe5156d 100644
--- a/yarn-project/sequencer-client/src/publisher/l1-publisher.ts
+++ b/yarn-project/sequencer-client/src/publisher/l1-publisher.ts
@@ -1,8 +1,9 @@
-import { type L2Block, type Signature, type TxHash } from '@aztec/circuit-types';
+import { type L2Block, type TxHash } from '@aztec/circuit-types';
 import { getHashedSignaturePayload } from '@aztec/circuit-types';
 import { type L1PublishBlockStats, type L1PublishProofStats } from '@aztec/circuit-types/stats';
 import { ETHEREUM_SLOT_DURATION, EthAddress, type Header, type Proof } from '@aztec/circuits.js';
 import { createEthereumChain } from '@aztec/ethereum';
+import { type Signature } from '@aztec/foundation/eth-signature';
 import { type Fr } from '@aztec/foundation/fields';
 import { createDebugLogger } from '@aztec/foundation/log';
 import { serializeToBuffer } from '@aztec/foundation/serialize';
@@ -255,7 +256,7 @@ export class L1Publisher {
       //        By simulation issue, I mean the fact that the block.timestamp is equal to the last block, not the next, which
       //        make time consistency checks break.
       await this.validateBlockForSubmission(block.header, {
-        digest,
+        digest: digest.toBuffer(),
         signatures: attestations ?? [],
       });
 
diff --git a/yarn-project/sequencer-client/src/sequencer/sequencer.test.ts b/yarn-project/sequencer-client/src/sequencer/sequencer.test.ts
index 0d990c56298..b7581454862 100644
--- a/yarn-project/sequencer-client/src/sequencer/sequencer.test.ts
+++ b/yarn-project/sequencer-client/src/sequencer/sequencer.test.ts
@@ -10,7 +10,6 @@ import {
   PROVING_STATUS,
   type ProvingSuccess,
   type ProvingTicket,
-  Signature,
   type Tx,
   TxHash,
   type UnencryptedL2Log,
@@ -31,6 +30,7 @@ import {
 import { Buffer32 } from '@aztec/foundation/buffer';
 import { times } from '@aztec/foundation/collection';
 import { randomBytes } from '@aztec/foundation/crypto';
+import { Signature } from '@aztec/foundation/eth-signature';
 import { type Writeable } from '@aztec/foundation/types';
 import { type P2P, P2PClientState } from '@aztec/p2p';
 import { type PublicProcessor, type PublicProcessorFactory } from '@aztec/simulator';
diff --git a/yarn-project/sequencer-client/src/sequencer/sequencer.ts b/yarn-project/sequencer-client/src/sequencer/sequencer.ts
index 6e4f3c157e9..69b8398d152 100644
--- a/yarn-project/sequencer-client/src/sequencer/sequencer.ts
+++ b/yarn-project/sequencer-client/src/sequencer/sequencer.ts
@@ -4,7 +4,6 @@ import {
   type L2Block,
   type L2BlockSource,
   type ProcessedTx,
-  Signature,
   Tx,
   type TxHash,
   type TxValidator,
@@ -15,13 +14,14 @@ import { type AllowedElement, BlockProofError, PROVING_STATUS } from '@aztec/cir
 import { type L2BlockBuiltStats } from '@aztec/circuit-types/stats';
 import {
   AppendOnlyTreeSnapshot,
-  AztecAddress,
   ContentCommitment,
-  EthAddress,
   GENESIS_ARCHIVE_ROOT,
   Header,
   StateReference,
 } from '@aztec/circuits.js';
+import { AztecAddress } from '@aztec/foundation/aztec-address';
+import { EthAddress } from '@aztec/foundation/eth-address';
+import { Signature } from '@aztec/foundation/eth-signature';
 import { Fr } from '@aztec/foundation/fields';
 import { createDebugLogger } from '@aztec/foundation/log';
 import { RunningPromise } from '@aztec/foundation/running-promise';
@@ -537,7 +537,7 @@ export class Sequencer {
     this.log.verbose(`Collected attestations from validators, number of attestations: ${attestations.length}`);
 
     // note: the smart contract requires that the signatures are provided in the order of the committee
-    return await orderAttestations(attestations, committee);
+    return orderAttestations(attestations, committee);
   }
 
   /**
@@ -666,12 +666,12 @@ export enum SequencerState {
  *
  * @todo: perform this logic within the memory attestation store instead?
  */
-async function orderAttestations(attestations: BlockAttestation[], orderAddresses: EthAddress[]): Promise<Signature[]> {
+function orderAttestations(attestations: BlockAttestation[], orderAddresses: EthAddress[]): Signature[] {
   // Create a map of sender addresses to BlockAttestations
   const attestationMap = new Map<string, BlockAttestation>();
 
   for (const attestation of attestations) {
-    const sender = await attestation.getSender();
+    const sender = attestation.getSender();
     if (sender) {
       attestationMap.set(sender.toString(), attestation);
     }
diff --git a/yarn-project/validator-client/src/duties/validation_service.ts b/yarn-project/validator-client/src/duties/validation_service.ts
index 3a4ec7e8c6d..6df10436870 100644
--- a/yarn-project/validator-client/src/duties/validation_service.ts
+++ b/yarn-project/validator-client/src/duties/validation_service.ts
@@ -1,5 +1,6 @@
 import { BlockAttestation, BlockProposal, type TxHash } from '@aztec/circuit-types';
 import { type Header } from '@aztec/circuits.js';
+import { Buffer32 } from '@aztec/foundation/buffer';
 import { keccak256 } from '@aztec/foundation/crypto';
 import { type Fr } from '@aztec/foundation/fields';
 
@@ -18,7 +19,7 @@ export class ValidationService {
    * @returns A block proposal signing the above information (not the current implementation!!!)
    */
   createBlockProposal(header: Header, archive: Fr, txs: TxHash[]): Promise<BlockProposal> {
-    const payloadSigner = (payload: Buffer) => this.keyStore.sign(payload);
+    const payloadSigner = (payload: Buffer32) => this.keyStore.signMessage(payload);
 
     return BlockProposal.createProposalFromSigner(header, archive, txs, payloadSigner);
   }
@@ -35,8 +36,8 @@ export class ValidationService {
   async attestToProposal(proposal: BlockProposal): Promise<BlockAttestation> {
     // TODO(https://github.com/AztecProtocol/aztec-packages/issues/7961): check that the current validator is correct
 
-    const buf = keccak256(proposal.getPayload());
-    const sig = await this.keyStore.sign(buf);
+    const buf = Buffer32.fromBuffer(keccak256(proposal.getPayload()));
+    const sig = await this.keyStore.signMessage(buf);
     return new BlockAttestation(proposal.header, proposal.archive, proposal.txs, sig);
   }
 }
diff --git a/yarn-project/validator-client/src/errors/validator.error.ts b/yarn-project/validator-client/src/errors/validator.error.ts
index 5cc3929962e..73c3eaf2729 100644
--- a/yarn-project/validator-client/src/errors/validator.error.ts
+++ b/yarn-project/validator-client/src/errors/validator.error.ts
@@ -2,7 +2,13 @@ import { type TxHash } from '@aztec/circuit-types/tx_hash';
 
 export class ValidatorError extends Error {
   constructor(message: string) {
-    super(message);
+    super(`Validator Error: ${message}`);
+  }
+}
+
+export class InvalidValidatorPrivateKeyError extends ValidatorError {
+  constructor() {
+    super('Invalid validator private key provided');
   }
 }
 
diff --git a/yarn-project/validator-client/src/key_store/interface.ts b/yarn-project/validator-client/src/key_store/interface.ts
index d55921b6dca..2b96c90377b 100644
--- a/yarn-project/validator-client/src/key_store/interface.ts
+++ b/yarn-project/validator-client/src/key_store/interface.ts
@@ -1,9 +1,18 @@
-import { type Signature } from '@aztec/circuit-types';
+import { type Buffer32 } from '@aztec/foundation/buffer';
+import { type Signature } from '@aztec/foundation/eth-signature';
 
 /** Key Store
  *
  * A keystore interface that can be replaced with a local keystore / remote signer service
  */
 export interface ValidatorKeyStore {
-  sign(message: Buffer): Promise<Signature>;
+  sign(message: Buffer32): Promise<Signature>;
+  /**
+   * Flavor of sign message that followed EIP-712 eth signed message prefix
+   * Note: this is only required when we are using ecdsa signatures over secp256k1
+   *
+   * @param message - The message to sign.
+   * @returns The signature.
+   */
+  signMessage(message: Buffer32): Promise<Signature>;
 }
diff --git a/yarn-project/validator-client/src/key_store/local_key_store.ts b/yarn-project/validator-client/src/key_store/local_key_store.ts
index 220b62fe409..736ee361a45 100644
--- a/yarn-project/validator-client/src/key_store/local_key_store.ts
+++ b/yarn-project/validator-client/src/key_store/local_key_store.ts
@@ -1,6 +1,6 @@
-import { Signature } from '@aztec/circuit-types';
-
-import { type PrivateKeyAccount, privateKeyToAccount } from 'viem/accounts';
+import { type Buffer32 } from '@aztec/foundation/buffer';
+import { Secp256k1Signer } from '@aztec/foundation/crypto';
+import { type Signature } from '@aztec/foundation/eth-signature';
 
 import { type ValidatorKeyStore } from './interface.js';
 
@@ -10,10 +10,10 @@ import { type ValidatorKeyStore } from './interface.js';
  * An implementation of the Key store using an in memory private key.
  */
 export class LocalKeyStore implements ValidatorKeyStore {
-  private signer: PrivateKeyAccount;
+  private signer: Secp256k1Signer;
 
-  constructor(privateKey: string) {
-    this.signer = privateKeyToAccount(privateKey as `0x{string}`);
+  constructor(privateKey: Buffer32) {
+    this.signer = new Secp256k1Signer(privateKey);
   }
 
   /**
@@ -22,10 +22,15 @@ export class LocalKeyStore implements ValidatorKeyStore {
    * @param messageBuffer - The message buffer to sign
    * @return signature
    */
-  public async sign(digestBuffer: Buffer): Promise<Signature> {
-    const digest: `0x${string}` = `0x${digestBuffer.toString('hex')}`;
-    const signature = await this.signer.signMessage({ message: { raw: digest } });
+  public sign(digest: Buffer32): Promise<Signature> {
+    const signature = this.signer.sign(digest);
+
+    return Promise.resolve(signature);
+  }
 
-    return Signature.from0xString(signature);
+  public signMessage(message: Buffer32): Promise<Signature> {
+    // Sign message adds eth sign prefix and hashes before signing
+    const signature = this.signer.signMessage(message);
+    return Promise.resolve(signature);
   }
 }
diff --git a/yarn-project/validator-client/src/validator.test.ts b/yarn-project/validator-client/src/validator.test.ts
index 4802656e5ce..fc870184fec 100644
--- a/yarn-project/validator-client/src/validator.test.ts
+++ b/yarn-project/validator-client/src/validator.test.ts
@@ -12,10 +12,16 @@ import { type MockProxy, mock } from 'jest-mock-extended';
 import { type PrivateKeyAccount, generatePrivateKey, privateKeyToAccount } from 'viem/accounts';
 
 import { makeBlockProposal } from '../../circuit-types/src/p2p/mocks.js';
-import { AttestationTimeoutError, TransactionsNotAvailableError } from './errors/validator.error.js';
+import { type ValidatorClientConfig } from './config.js';
+import {
+  AttestationTimeoutError,
+  InvalidValidatorPrivateKeyError,
+  TransactionsNotAvailableError,
+} from './errors/validator.error.js';
 import { ValidatorClient } from './validator.js';
 
 describe('ValidationService', () => {
+  let config: ValidatorClientConfig;
   let validatorClient: ValidatorClient;
   let p2pClient: MockProxy<P2P>;
   let validatorAccount: PrivateKeyAccount;
@@ -27,7 +33,7 @@ describe('ValidationService', () => {
     const validatorPrivateKey = generatePrivateKey();
     validatorAccount = privateKeyToAccount(validatorPrivateKey);
 
-    const config = {
+    config = {
       validatorPrivateKey: validatorPrivateKey,
       attestationPoolingIntervalMs: 1000,
       attestationWaitTimeoutMs: 1000,
@@ -36,6 +42,11 @@ describe('ValidationService', () => {
     validatorClient = ValidatorClient.new(config, p2pClient);
   });
 
+  it('Should throw error if an invalid private key is provided', () => {
+    config.validatorPrivateKey = '0x1234567890123456789';
+    expect(() => ValidatorClient.new(config, p2pClient)).toThrow(InvalidValidatorPrivateKeyError);
+  });
+
   it('Should create a valid block proposal', async () => {
     const header = makeHeader();
     const archive = Fr.random();
@@ -46,17 +57,17 @@ describe('ValidationService', () => {
     expect(blockProposal).toBeDefined();
 
     const validatorAddress = EthAddress.fromString(validatorAccount.address);
-    expect(await blockProposal.getSender()).toEqual(validatorAddress);
+    expect(blockProposal.getSender()).toEqual(validatorAddress);
   });
 
   it('Should a timeout if we do not collect enough attestations in time', async () => {
-    const proposal = await makeBlockProposal();
+    const proposal = makeBlockProposal();
 
     await expect(validatorClient.collectAttestations(proposal, 2)).rejects.toThrow(AttestationTimeoutError);
   });
 
   it('Should throw an error if the transactions are not available', async () => {
-    const proposal = await makeBlockProposal();
+    const proposal = makeBlockProposal();
 
     // mock the p2pClient.getTxStatus to return undefined for all transactions
     p2pClient.getTxStatus.mockImplementation(() => undefined);
diff --git a/yarn-project/validator-client/src/validator.ts b/yarn-project/validator-client/src/validator.ts
index 1c8442ef367..890e413ffff 100644
--- a/yarn-project/validator-client/src/validator.ts
+++ b/yarn-project/validator-client/src/validator.ts
@@ -1,5 +1,6 @@
 import { type BlockAttestation, type BlockProposal, type TxHash } from '@aztec/circuit-types';
 import { type Header } from '@aztec/circuits.js';
+import { Buffer32 } from '@aztec/foundation/buffer';
 import { type Fr } from '@aztec/foundation/fields';
 import { createDebugLogger } from '@aztec/foundation/log';
 import { sleep } from '@aztec/foundation/sleep';
@@ -7,7 +8,11 @@ import { type P2P } from '@aztec/p2p';
 
 import { type ValidatorClientConfig } from './config.js';
 import { ValidationService } from './duties/validation_service.js';
-import { AttestationTimeoutError, TransactionsNotAvailableError } from './errors/validator.error.js';
+import {
+  AttestationTimeoutError,
+  InvalidValidatorPrivateKeyError,
+  TransactionsNotAvailableError,
+} from './errors/validator.error.js';
 import { type ValidatorKeyStore } from './key_store/interface.js';
 import { LocalKeyStore } from './key_store/local_key_store.js';
 
@@ -42,7 +47,12 @@ export class ValidatorClient implements Validator {
   }
 
   static new(config: ValidatorClientConfig, p2pClient: P2P) {
-    const localKeyStore = new LocalKeyStore(config.validatorPrivateKey);
+    if (!config.validatorPrivateKey) {
+      throw new InvalidValidatorPrivateKeyError();
+    }
+
+    const privateKey = validatePrivateKey(config.validatorPrivateKey);
+    const localKeyStore = new LocalKeyStore(privateKey);
 
     const validator = new ValidatorClient(
       localKeyStore,
@@ -154,3 +164,11 @@ export class ValidatorClient implements Validator {
     }
   }
 }
+
+function validatePrivateKey(privateKey: string): Buffer32 {
+  try {
+    return Buffer32.fromString(privateKey);
+  } catch (error) {
+    throw new InvalidValidatorPrivateKeyError();
+  }
+}
diff --git a/yarn-project/yarn.lock b/yarn-project/yarn.lock
index 0a64d09d724..159c6eecb4a 100644
--- a/yarn-project/yarn.lock
+++ b/yarn-project/yarn.lock
@@ -677,6 +677,7 @@ __metadata:
     supertest: ^6.3.3
     ts-node: ^10.9.1
     typescript: ^5.0.4
+    viem: ^2.7.15
     zod: ^3.22.4
   languageName: unknown
   linkType: soft