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Cryptography news and discussions

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... is the art of creating mathematical / information theoretic assurances for who can do what with data, including but not limited to 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 is intended for links and discussions surrounding the theory and practice of modern and strong cryptography.

Please note that this is a technical subreddit, not a political one! The focus is on the algorithms and the security of the implementations.

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(along with normal reddiquette)

Don't forget to read our RULES PAGE! The rules listed there are also used as this sub's report reasons. The quick version;

  • Assume good faith and be kind. This is a friendly subreddit.
  • Codes, simple ciphers, ARGs, and other such "weak crypto" don't belong here. (Rule of thumb: If a desktop computer can break a code in less than an hour, it's not strong crypto.) You're probably looking for /r/codes.
  • Do not ask people to break your cryptosystem without first sharing the algorithm. Sharing just the output is like...
  • "Crack this cipher" challenges also belong in /r/codes unless they're based on interesting crypto implementation bugs, e.g. weak RSA keys.
  • Familiarize yourself with the following before posting a question about a novel cryptosystem, or else the risk is nobody will take their time to answer:
  • Kerckhoffs's principle
  • Schneier's Law
  • Don't use this sub to cheat on competitions or challenges! You're expected to solve such problems yourself. You may ask for help to understand it, but you should disclose the source.
  • Systems that use crypto are not necessarily relevant here, e.g. Bitcoin. Maybe try /r/cryptocurrency? Political news also very rarely belong here. See the list of related subs below for alternatives. Remember that this sub is focused on the algorithms, and isn't political.


Other subreddits that may be of interest:


  • /r/algorithms
  • /r/mathematics, /r/math


  • /r/netsec - Network Security
  • /r/compsec - Local computer security
  • /r/websec - Security in the browser
  • /r/security - General security subreddit
  • /r/privacy - General privacy subreddit
  • /r/compsci & /r/ComputerScience - Development and application of algorithms

Educational, hobbyist:

  • /r/gpgpractice - Do your testing here
  • /r/stanfordcrypto
  • /r/codes - General code cracking

Political and in the news:

  • /r/privacypatriots/
  • /r/NSAleaks - Snowden documents and more
  • /r/restorethefourth


  • /r/gpg (fairly empty)
  • /r/bitcoin, /r/cryptocurrency - crypto applied to money


  • /r/cryptography
  • /r/encryption
  • /r/weboftrust (fairly empty)
  • /r/capabilities - A type of security model
  • /r/Intelligence - Espionage

Memes and low effort submissions:

  • /r/shittycrypto

Feel free to message the moderators with suggestions for how to improve this subreddit, as well as for requesting adding links in the sidebar.

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