cryptographic primitive process - MathOverflow most recent 30 from http://mathoverflow.net 2013-05-22T02:49:24Z http://mathoverflow.net/feeds/question/119735 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://mathoverflow.net/questions/119735/cryptographic-primitive-process cryptographic primitive process Auth 2013-01-24T08:55:38Z 2013-04-04T18:43:12Z <p>Is there a cryptographic primitive process/method for creating cryptographic tools like symmetric encryption/decryption, Hash code generator, MAC generator and Random number generator?</p> <pre><code> Or </code></pre> <p>Is it possible to create cryptographic tools like symmetric encryption/decryption, Hash code generator, MAC generator and Random number generator using the same cryptographic primitive process/method?</p> http://mathoverflow.net/questions/119735/cryptographic-primitive-process/119737#119737 Answer by Gro-Tsen for cryptographic primitive process Gro-Tsen 2013-01-24T09:35:44Z 2013-01-24T09:35:44Z <p>The <a href="http://www.schneier.com/threefish.html" rel="nofollow">Threefish</a> block cipher, for example, is well equipped to do all the things you mention (it's a symmetric cipher which was built for the purpose of creating the Skein hash function, a SHA-3 finalist; the Skein paper explains how it can easily be used as a MAC and RNG).</p> <p>That being said, I don't think MathOverfow was the right place to ask this particular question.</p> http://mathoverflow.net/questions/119735/cryptographic-primitive-process/126545#126545 Answer by Stephan Müller for cryptographic primitive process Stephan Müller 2013-04-04T18:43:12Z 2013-04-04T18:43:12Z <p>Hi, </p> <p>from any blockcipher (for example as Threefish as mentioned by Gro-Tsen) you can build various other primitives. This is heavily related to their mode of operation. You can find basic pointers in <a href="http://en.wikipedia.org/wiki/Block_cipher#Relation_to_other_cryptographic_primitives" rel="nofollow">wikipedia's article on block ciphers</a>.But usually one uses dedicated algorithms for different problems like encryption, hashes, etc..</p> <p>However there are other much more general approaches, for example many primitives can be seen as instances of <a href="http://en.wikipedia.org/wiki/Sponge_function" rel="nofollow">sponge constructions</a>. But it is hard to guess what you are looking for. </p> <p>Also 'cryptographic primitive' is more an idea rather than a fixed notion. It is distinguishes 'cryptographic algorithms' from 'cryptographic schemes'. There is a beautiful paper from U.Maurer: <a href="http://www.crypto.ethz.ch/publications/abstract.html?label=Maurer11" rel="nofollow">Constructive cryptography</a> about 'pasting' primitives.</p> <p>All this said, it seems to be a question for <a href="http://crypto.stackexchange.com/" rel="nofollow">crypto.stackexchange</a>. Also you should provide more background in what (and why) your are interested.</p>