Cypherpunk refers to people who advocate the challenging of social and political norms through the use of cryptography. They aid in this effort through the development of privacy tools meant to counteract the surveillance of governments and other entities.
Email Community
The community started by a group of hackers in the early 1990s. It all began with an email list put together by Eric Hughes, Timothy C. May, and John Gilmore. The ideology pushed free and open source software as a means to its end.
At its peak, it was rumored to have near 2,000 people on the mailing list.
Principles
Eric Hughes wrote in the Cypherpunk Manifesto:
"Privacy is necessary for an open society in the electronic age. ... We cannot expect governments, corporations, or other large, faceless organizations to grant us privacy ... We must defend our own privacy if we expect to have any. ... Cypherpunks write code. We know that someone has to write software to defend privacy, and ... we're going to write it."
The movement was well ahead of its time and did have insight into the future. One of the key principles is privacy in communications and data retention. The idea was to have a guarantee of privacy that came from physics and mathematics, not laws.
Their original battleground was over encryption, which the government was looking to ban. The view is that privacy is a fundamental right which governments cannot take away.
Bitcoin
The pseudonym Satoshi Nakamoto is believed to have come from the cypherpunk world. One of the accused, Nick Szabo, was well known in the movement.
Even without knowing the individual, it is easy to connect the dots between earlier forms of digital money such as Bit Gold (Szabo's development), ECash (created by David Chaum) and Bitcoin. The basic technology of relying upon computing power for security was consistent throughout.
Bitcoin was created as a system of money that was outside the control of government. This is where the principles espoused by the cypherpunks comes through clearly.