Yesterday I went to the 4th Bay Area Mathematical Adventures for the 2004-2005 school year, at the San Jose State University. Steven G. Krantz was our speaker, and talked to us mainly about RSA encryption. It was pretty interesting, although some parts were hard to understand.

RSA is an encryption scheme that was developed in 1978 by three people: R. Rivest, A. Shamir, and L. Adleman. It’s based around the fact that factoring large numbers takes exponential time for present-day computers, and is not a feasible task.

RSA is a public-key encryption system, which means that you can send a message to someone by using their public key, which is distributed to everyone. Then, to decrypt the message, a private key is needed. This is kept secret, and only the recipient knows this. Therefore, no one else can read the message.

There’s a lot of math involved behind the scenes, and I found that this site explains it pretty well.

RSA is an industry-standard encryption scheme used everywhere–by the government, companies, educational institutions, and even the general public. Secure Sockets Layer, or SSL uses RSA encryption. They may not know it, but when people enter financial data, purchase items online, read email securely, or even use their credit cards at a store, RSA encryption is being employed to protect their sensitive information.