The aim of /r/Physics is to build a subreddit frequented by physicists, scientists, and those with a passion for physics. Papers from physics journals (free or otherwise) are encouraged. Posts should be pertinent, meme-free, and generate a discussion about physics. Please report trolls and intentionally misleading comments.
A subreddit to draw simple physics questions away from /r/physics. No real rules; ask away. If your basic physics question isn't answered in a day, you can post it to /r/physics if you mention that you didn't get an answer on /r/AskPhysics (unless it's a homework-related physics question).
Cryptography is the art of creating mathematical assurances for who can do what with data, including but not limited the classical example of encrypting messages so that only the key-holder can read it. Cryptography lives at an intersection of math, programming, and computer science. This subreddit covers the theory and practice of modern and *strong* cryptography, and it is a technical subreddit focused on the algorithms and implementations of cryptography.
A subreddit dedicated to hacking and hackers. Constructive collaboration and learning about exploits, industry standards, grey and white hat hacking, new hardware and software hacking technology, sharing ideas and suggestions for small business and personal security.
/r/btc was created to foster and support free and open Bitcoin discussion, Bitcoin news, and exclusive AMA (Ask Me Anything) interviews from top Bitcoin industry leaders! Bitcoin is the currency of the Internet. A distributed, worldwide, decentralized digital money. Unlike traditional currencies such as dollars, bitcoins are issued and managed without the need for any central authority whatsoever.