Question:

There are three main types of cryptographic algorithms: (1) secret key, (2) public key, and (3) hash functions. Pick an algorithm for any one of these types (e.g., DES, AES, RSA, MD5) and describe how it works and where it is applied (For example SSL uses 3DES or DES) for message encryption. Use your own words. When you pick an algorithm, try not to repeat. Be sure to reference your sources.

Answer:

RSA stands for Ron Rivest, Adi Shamir and Leonard Adelman. The three are the first to publicly described RSA. RSA is algorithm used by modern computers to encrypt and decrypt messages. It is an asymmetric cryptographic algorithm, meaning that works of two different keys. The private and public keys, because one of them is kept private while the other can be given to everyone respectively. The algorithm capitalizes on the fact that there is no efficient way to factor very large (100-200 digit) numbers. The main challenge in this algorithm is selection and generation of the public and private keys.

The mechanism behind RSA algorithm. Using an encryption key (e,n), the algorithm is as follows:

Represent the message as an integer between 0 and (n-1). Large messages can be broken up into a number of blocks. Each block would then be represented by an integer in the same range.

Encrypt the message by raising it to the eth power modulo n. The result is a ciphertext message C.

To decrypt ciphertext message C, raise it to another power d modulo n

The encryption key (e,n) is made public. The decryption key (d,n) is kept private by the user.