Clear TODOs from accountability doc (#216)

* Clear TODOs from accountability doc

* Add note about master/release

* Add missing space

README.md

@@ -30,11 +30,9 @@ VSP will add the ticket to a pool of always-online voting wallets.
   stats. An admin page enables searching for tickets and downloading database
   backups.
 
-- **Two-way accountability** - All vspd requests must be signed with a private
-  key corresponding to the relevant ticket, and all vspd responses are signed
-  by with a private key known only by the server. This enables both the client
-  and the server to prove to outside observers if their counterparty is
-  misbehaving. For more detail, and examples, read
+- **Two-way accountability** - All vspd requests and responses are signed by
+  their sender, which enables both the client and the server to hold each other
+  accountable in the case of misbehaviour. For more detail, and examples, read
   [two-way-accountability.md](./docs/two-way-accountability.md).
 
 - **Dynamic fees** - Clients must request a new fee address and amount for every

docs/deployment.md

@@ -11,6 +11,11 @@ familiarity with Decred software and a level of sysadmin experience.
 Compiled binaries are not provided for vspd - VSP operators are expected to
 build vspd from source.
 
+When deploying vspd to production, always build all binaries from release
+branches.
+Neither vspd nor its dependencies (dcrd/dcrwallet) should be built from master
+when handling mainnet tickets.
+
 ### Fee wallet
 
 A wallet should be created to collect VSP fees. Ideally this would be a cold

docs/two-way-accountability.md

@@ -1,19 +1,43 @@
 # Two-way Accountability
 
-- When vspd is started for the first time, it generates a ed25519 keypair and
-  stores it in the database. This key is used to sign all API responses, and the
-  signature is included in the response header `VSP-Server-Signature`.
+In order to support two-way accountability, all vspd requests must be signed
+with a private key corresponding to the relevant ticket, and all vspd responses
+are signed by with a private key known only by the server.
 
-- Every client request which references a ticket should include a HTTP header
+## Client
+
+### Client Request Signatures
+
+Every client request which references a ticket should include a HTTP header
 `VSP-Client-Signature`. The value of this header must be a signature of the
 request body, signed with the commitment address of the referenced ticket.
 
-## Examples
+### Client Accountability Example
 
-### Server does not vote ticket
+A misbehaving user may attempt to discredit a VSP operator by falsely claiming
+that the VSP did not vote a ticket according to the voting preferences selected
+by the user.
 
-TODO
+In this case, the VSP operator can reveal the request signed by the user which
+set the voting preferences, and demonstrate that this matches the voting
+preferences which were recorded on the blockchain. It would then be incumbent on
+the user to provide a signed request/response pair with a later timestamp to
+demonstrate that the operator is being dishonest.
 
-### Client denies changing their voting preferences
+## Server
 
-TODO
+### Server Response Signatures
+
+When vspd is started for the first time, it generates a ed25519 keypair and
+stores it in the database. This key is used to sign all API responses, and the
+signature is included in the response header `VSP-Server-Signature`.
+
+### Server Accountability Example
+
+A misbehaving server may fail to vote several tickets for which a user has paid
+valid fees.
+
+In this case, the user can reveal responses signed by the server which
+demonstrate that the server has acknowledged receipt of the fees, and all
+information necessary to have voted the ticket. It would then be incumbent on
+the server to explain why these tickets were not voted.