implementing aliases #20

src/Core/Model/audit.jl

@@ -240,7 +240,6 @@ function audit(ledger::BallotBoxLedger)
     return true
 end
 
-
 function isbinding(chain::BraidChainLedger, bbox::BallotBoxLedger)
 
     # records must be part of the chain
@@ -250,10 +249,17 @@ function isbinding(chain::BraidChainLedger, bbox::BallotBoxLedger)
     braid_index = bbox.proposal.anchor.index
     braid_receipt = chain[braid_index]::BraidReceipt
 
-    voters = Set(output_members(braid_receipt))
-
+    # voters = Set(output_members(braid_receipt))
+    # for record in bbox
+    #     issuer(record) in voters || return false
+    # end
+
+    # Checking aliases. This also checks membership
+    members = output_members(braid_receipt)
+
     for record in bbox
-        issuer(record) in voters || return false
+        1 <= record.alias <= length(members) || return false
+        members[record.alias] == issuer(record.vote) || return false
     end
 
     return true

src/Core/Model/ballotbox.jl

@@ -350,6 +350,7 @@ that they had cast their vote without revealing the link to the vote.
 """
 struct CastRecord
     vote::Vote
+    alias::Int
     timestamp::DateTime
 end
 
@@ -386,6 +387,7 @@ and that could be a good thing!
 """
 struct CastReceipt
     vote::Digest
+    alias::Digest # H(alias|vote)
     timestamp::DateTime
 end
 
@@ -402,7 +404,17 @@ end
 
 Construct a CastReceipt from a CastRecord with a provided hasher function.
 """
-receipt(record::CastRecord, hasher::HashSpec) = CastReceipt(digest(record.vote, hasher), record.timestamp)
+function receipt(record::CastRecord, hasher::HashSpec)
+
+    vote_hash = digest(record.vote, hasher)
+
+    vote_bytes = canonicalize(record.vote)
+    alias_bytes = reinterpret(UInt8, [UInt32(record.alias)])
+    alias_commit = digest(UInt8[alias_bytes..., vote_bytes...], hasher)
+
+    return CastReceipt(vote_hash, alias_commit, record.timestamp)
+end
+
 receipt(record::CastRecord, spec) = receipt(record, hasher(spec))
 
 

src/Core/ProtocolSchema.jl

@@ -225,6 +225,7 @@ revoting would be as hard as monitoring the submitted votes.
 """
 struct CastAck
     receipt::CastReceipt
+    alias::Int
     ack::AckInclusion{BallotBoxState}
 end
 

src/Server/Controllers/ballotbox.jl

@@ -236,9 +236,10 @@ Compute an acknowledgment for record inclusion at `index`.
 function ack_cast(ballotbox::BallotBoxController, N::Int)
 
     ack = ack_leaf(ballotbox, N)
-    _receipt = receipt(ballotbox, N)
+    record = ballotbox[N] 
+    _receipt = receipt(record, ballotbox.ledger.spec)
 
-    return CastAck(_receipt, ack)    
+    return CastAck(_receipt, record.alias, ack) 
 end
 
 """
@@ -375,8 +376,9 @@ function commit!(ballotbox::BallotBoxController, timestamp::DateTime, signer::Si
 
     for vote in ballotbox.queue
 
+        alias = findindex(issuer(vote), ballotbox.voters)
         # an ideal place to form a blind signature on the user's request.
-        record = CastRecord(vote, timestamp)
+        record = CastRecord(vote, alias, timestamp)
         push!(ballotbox, record)
 
     end