RSA
Many researchers have spent a great deal of time trying to devise public-key
algorithms. In 1978, a trio of researchers at M.I.T. discovered and algorithm that has
withstood all attempts to crack the scheme. The algorithm is named RSA using the
initials of the last name of the three researchers. About the only drawback of the
algorithm is the key length required for good security. The RSA algorithm requires keys
of at least 1024 bits. This is compared to a key length of 128 bits for AES and thus the
algorithm is very slow in comparison. So, the obvious question is “If the algorithm is so
slow, what good is it?” The answer is that in practice, RSA is ideal for distributing a
single session symmetric key to a user and then using AES or Triple DES for the
encryption and decryption of large amounts of data. While RSA is not the only publickey algorithm in existence, it is probably the most widely used and is the only one
discussed in this paper.