*Choose Index below for a list of all words and phrases defined in this glossary.*

**RSA algorithm** - This is the name of the first published asymmetric or public key algorithm. It is named after its inventors, Rivest, Shamir and Edelman. RSA has been known about for over 20 years now, and has been subjected to considerable academic research to find out if it has any weaknesses, and, so far, none have been published. It has key lengths of 512, 1024 and 2048 bits (binary digits), so the maximum possible number of unique keys (and hence unique users) that could exist range from 2 raised to the power 512 to 2 raised to the power 2048. (For the non-mathematicians 2 raised to the power of 100 is calculated by multiplying 2 by itself 100 times, giving a value 1,267,650,600,228,229,401,496,703,205,376 and that value doubles each time you raise it by multiplying by two. (2 to the power 2048 doesn't fit very readably on this page and is difficult to proof read.)

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*Actic Soft, 08 August 2011 08:22:44, http://www.articsoft.com/it_security.htm *

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**RSA algorithm** - The RSA algorithm was invented by Ronald L. Rivest, Adi Shamir, and Leonard Adleman in 1977 and released into the public domain on September 6, 2000.

Public-key systems~~or asymmetric cryptography~~use two different keys with a mathematical relationship to each other. Their protection relies on the premise that knowing one key will not help you figure out the other. The RSA algorithm uses the fact that it's easy to multiply two large prime numbers together and get a product. But you can't take that product and reasonably guess the two original numbers, or guess one of the original primes if only the other is known. The public key and private keys are carefully generated using the RSA algorithm; they can be used to encrypt information or sign it.

PKCS 1 and other standards contain rules for using this algorithm and the key pairs that it generates.

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*Source: RSA, 21 August 2011 09:16:03, http://www.rsa.com/glossary/ *

Data Quality Glossary. A free resource from GRC Data Intelligence. For comments, questions or feedback: dqglossary@grcdi.nl