MOVE_VALIDATE_TICKET — Group 20, Code 4

Destination validates a pickup ticket back to the source; the source then advances the coin to MOVED_OUT. Inter-RAIDA, CMAC-authenticated.

Design-stage — parameters are a first draft

Field sizes are drafted from raidax/ideas_for_suspect_raida_servers.txt (Addenda 5–7) and are not final or implementation-verified. The body is encrypted per the header ENC_CODE; see below.

Phase I — essential

This command is part of the Phase I minimum needed for a coin to move from root to suspect (and back) and be trusted by a workstation. Server-to-server ticket check; the move cannot commit without it.

How it works

This command is spoken between two servers, not by a user. When a coin moves, the source server (the one losing authority) hands out a one-time ticket — a random number that acts as a claim check. The destination server, before it accepts responsibility for the coin, calls back to the source to ask: “is this ticket genuine, and which coin does it stand for?”

That callback is this command. The two servers share a secret key (each suspect is enrolled with its own coin for exactly this purpose), so the whole exchange is authenticated with AES-CMAC and cannot be forged by an outsider. When the source confirms the ticket, it also permanently stops answering for that coin (it records a “moved-out” marker), which is what guarantees a coin is never claimed as live on two servers at once.

Direction & encryption

  • Direction: dest → source
  • ENC_CODE: 7 (K_rs, inter-RAIDA)

Request Body parameters

FieldBytesDescription
ticket16The pickup ticket issued by the source.
DN1Denomination of coin X (echo for validation).
SN4Serial number of coin X (echo for validation).
CMAC16AES-CMAC over the request under K_rs.

Response Body parameters

FieldBytesDescription
valid11 = ticket good.
DN1Denomination of the coin the ticket names.
SN4Serial number of the coin the ticket names.
target_id2Confirmed destination server id.
seq4Move sequence number.
CMAC16AES-CMAC over the response under K_rs.