diff --git a/beacon_chain/beacon_node.nim b/beacon_chain/beacon_node.nim
index f5d8dd749..2c98d2f35 100644
--- a/beacon_chain/beacon_node.nim
+++ b/beacon_chain/beacon_node.nim
@@ -1,7 +1,7 @@
 import
   os, net, sequtils,
   asyncdispatch2, chronicles, confutils, eth_p2p, eth_keys,
-  spec/[beaconstate, datatypes, helpers, crypto], conf, time, fork_choice,
+  spec/[beaconstate, datatypes, helpers, crypto], conf, time, fork_choice, ssz,
   beacon_chain_db, validator_pool, mainchain_monitor,
   sync_protocol, gossipsub_protocol, trusted_state_snapshots
 
@@ -139,7 +139,9 @@ proc proposeBlock(node: BeaconNode,
   #   proposal.specials.add r
 
   var signedData: ProposalSignedData
-  # TODO: populate the signed data
+  signedData.slot = node.beaconState.slot
+  signedData.shard = BEACON_CHAIN_SHARD_NUMBER
+  signedData.blockRoot.data = hash_tree_root(proposal)
 
   proposal.signature = await validator.signBlockProposal(signedData)
   await node.network.broadcast(topicBeaconBlocks, proposal)
diff --git a/beacon_chain/validator_pool.nim b/beacon_chain/validator_pool.nim
index f29cc0ab9..441e16604 100644
--- a/beacon_chain/validator_pool.nim
+++ b/beacon_chain/validator_pool.nim
@@ -1,7 +1,7 @@
 import
   tables, random,
-  asyncdispatch2,
-  spec/[datatypes, crypto, digest], randao
+  asyncdispatch2, milagro_crypto,
+  spec/[datatypes, crypto, digest], randao, ssz
 
 type
   ValidatorKind = enum
@@ -44,8 +44,10 @@ proc signBlockProposal*(v: AttachedValidator,
                         proposal: ProposalSignedData): Future[ValidatorSig] {.async.} =
   if v.kind == inProcess:
     await sleepAsync(1)
-    # TODO:
-    # return sign(proposal, v.privKey)
+    let proposalRoot = hash_tree_root(proposal)
+
+    # TODO: Should we use proposalRoot as data, or digest in regards to signature?
+    return signMessage(v.privKey, proposalRoot)
   else:
     # TODO:
     # send RPC
@@ -56,8 +58,10 @@ proc signAttestation*(v: AttachedValidator,
   # TODO: implement this
   if v.kind == inProcess:
     await sleepAsync(1)
-    # TODO:
-    # return sign(proposal, v.privKey)
+
+    let attestationRoot = hash_tree_root(attestation)
+    # TODO: Should we use attestationRoot as data, or digest in regards to signature?
+    return signMessage(v.privKey, attestationRoot)
   else:
     # TODO:
     # send RPC