# Sequence diagram for RLN Relay protocol (publishing,routing, and slashing)
msc {
  hscale="1",
  wordwraparcs=true;

  a [label="RLN-Relay Node: Publisher"],
  b [label="RLN-Relay Node: Router"],
  c [label="RLN-Relay Node"],
  d [label="RLN-Relay Node"],
  e [label="Membership Contract"];

  # a rbox a [label="RLN-Relay Node: Publisher"],
  # b rbox b [label="RLN-Relay Node: Router"],
  # c rbox c [label="RLN-Relay Node"],
  # d rbox d [label="RLN-Relay Node"],
  # e note e [label="Membership Contract"];
  |||;
  b box b [label=" \n nullifierMap= [(nullifier, shareX, shareY)...] \n \n  Initialize an empty map of the received nullifiers \n "],
  c box c [label=" \n nullifierMap= [(nullifier, shareX, shareY)...] \n \n Initialize an empty map of the received nullifiers \n "],
  d box d [label=" \n nullifierMap= [(nullifier, shareX, shareY)...] \n \n Initialize an empty map of the received nullifiers \n "];
  |||;
  ...,
  a -> a [label="Keep track of epoch"],
  b -> b [label="Keep track of epoch"],
  c -> c [label="Keep track of epoch"],
  d -> d [label="Keep track of epoch"];
  a box a [label=" \n Message: the intended message \n \n epoch: the current epoch \n "];
  a box a [label=" \n  A(x) = sk + H(sk, epoch)x \n \n shareX = H(message), shareY = A(shareX) \n \n nullifier = H(H(sk,epoch)) \n "];
  a box a [label="  \n  zkProof: generate the proof using zkSNARK \n "];
  |||;
  a => b [label="Message, epoch, proofBundle:(shareX, shareY, nullifier, zkProof) \n "];
  b box b [label="1. If the received epoch is far from the current epoch"];
  b -x c [label="Do not relay"];
  b box b [label=" \n 2. If verification of zkProof failed \n "];
  b -x c [label="Do not relay"];
  b box b [label=" \n 3. If identical nullifier exists in the nullifierMap, \n \n extract the publisher sk \n "];
  b -x c [label="Do not relay"];
  b => e [label="Slash the publisher: Unlbock the deposit associated with sk"];
  e => b [label="x ETH"];
  b box b [label=" \n 4. If none of  1-3 happens, update the nullifierMap \n "];
  b => c [label="Relay"];
  b => d [label="Relay"];
}