diff --git a/src/avalanche/processor.h b/src/avalanche/processor.h
--- a/src/avalanche/processor.h
+++ b/src/avalanche/processor.h
@@ -286,6 +286,12 @@
     CPubKey getSessionPubKey() const;
     bool sendHello(CNode *pfrom) const;
 
+    /**
+     * Build and return the challenge whose signature we expect a peer to
+     * include in his AVAHELLO message.
+     */
+    uint256 buildRemoteSighash(CNode *pfrom) const;
+
     std::vector<avalanche::Peer> getPeers() const;
     std::vector<NodeId> getNodeIdsForPeer(PeerId peerId) const;
 
@@ -298,6 +304,12 @@
     std::vector<CInv> getInvsForNextPoll(bool forPoll = true);
     NodeId getSuitableNodeToQuery();
 
+    /**
+     * Build and return the challenge whose signature is included in the
+     * AVAHELLO message that we send to a peer.
+     */
+    uint256 buildLocalSighash(CNode *pfrom) const;
+
     friend struct ::avalanche::AvalancheTest;
 };
 
diff --git a/src/avalanche/processor.cpp b/src/avalanche/processor.cpp
--- a/src/avalanche/processor.cpp
+++ b/src/avalanche/processor.cpp
@@ -397,6 +397,26 @@
     return sessionKey.GetPubKey();
 }
 
+uint256 Processor::buildLocalSighash(CNode *pfrom) const {
+    CHashWriter hasher(SER_GETHASH, 0);
+    hasher << peerData->delegation.getId();
+    hasher << pfrom->GetLocalNonce();
+    hasher << pfrom->nRemoteHostNonce;
+    hasher << pfrom->GetLocalExtraEntropy();
+    hasher << pfrom->nRemoteExtraEntropy;
+    return hasher.GetHash();
+}
+
+uint256 Processor::buildRemoteSighash(CNode *pfrom) const {
+    CHashWriter hasher(SER_GETHASH, 0);
+    hasher << pfrom->m_avalanche_state->delegation.getId();
+    hasher << pfrom->nRemoteHostNonce;
+    hasher << pfrom->GetLocalNonce();
+    hasher << pfrom->nRemoteExtraEntropy;
+    hasher << pfrom->GetLocalExtraEntropy();
+    return hasher.GetHash();
+}
+
 bool Processor::sendHello(CNode *pfrom) const {
     if (!peerData) {
         // We do not have a delegation to advertise.
@@ -407,13 +427,7 @@
     SchnorrSig sig;
 
     {
-        CHashWriter hasher(SER_GETHASH, 0);
-        hasher << peerData->delegation.getId();
-        hasher << pfrom->GetLocalNonce();
-        hasher << pfrom->nRemoteHostNonce;
-        hasher << pfrom->GetLocalExtraEntropy();
-        hasher << pfrom->nRemoteExtraEntropy;
-        const uint256 hash = hasher.GetHash();
+        const uint256 hash = buildLocalSighash(pfrom);
 
         if (!sessionKey.SignSchnorr(hash, sig)) {
             return false;