Secure client-server communication

A server comprising:

• an interface;
• a memory to store at least one part of a blockchain;
• a processor to:
• receive, from a client device on the interface, a client message indicating use of blockchain mode to establish a secure connection between the client device and the server;
• generate a server message indicating use of the blockchain mode;
• send the server message to the client device on the interface;
• and
• securely communicate with the client device, on the interface, using at least one cryptographic key generated from information including cryptographic key generation information stored in the blockchain.

A method comprising:

• storing at least one part of a blockchain;
• generating a client message indicating use of blockchain mode to establish a secure connection between a client device and a server;
• sending the client message to the server;
• receiving, from the server, a server message indicating use of the blockchain mode;
• and
• securely communicating with the server using at least one cryptographic key generated from information including cryptographic key generation information stored in the blockchain.