Embodiments of the present invention may provide techniques by which replay attacks in a blockchain network may be efficiently resisted, while preserving valid user permissions and privacy in the blockchain network. For example, in an embodiment of the present invention, in a network of computer systems, a method of communication may comprise at a user computer system, generating a security value that is to be used only once, generating a message signed with a security certificate and including the security value, and transmitting the message over the network of computer systems.