A cypherpunk is usually someone who believes in the use of cryptography to affect social and political change, with a strong emphasis of increased privacy through cryptography. Satoshi Nakamoto first announced Bitcoin in the Cypherpunk mailing list, which is the predominant communication channel for the cypherpunk movement. In addition to Satoshi, some other notable cypherpunks associated with Bitcoin include Hal Finney, the first user of Bitcoin after Satoshi and Adam Back, the inventor of HashCash after which Bitcoin’s proof of work is modeled.