Multisignature Lock Contract

Multisignature (also called multisig) is an authorization mechanism that requires M signatures of N public keys.[1] In Blacknet, it is implemented as a lock that can be created then spent. Example application of 2-of-3 multisig is a marketplace: buyer, seller, escrow.[2]

Replay Attack

A replay attack is an attack, in which a legitimate data is maliciously repeated. An adversary could try to resubmit a transaction or its data to the network for dishonest execution. An ordinary transaction signature is committed to the transaction header that cannot be replayed. A spending multi-signature is committed to the contract id that also cannot be replayed. For creating multi-signature following data is hashed: sender id, sender sequence number, transaction data index number, transaction data without signatures.


RPC API is not yet implemented.


  1. Satoshi Nakamoto, Bitcoin v0.1 released, .
  2. jenncloud, OpenBazaar Dispute Resolution Guidelines, .