RC2 is the variable key-size block cipher invented by Rivest for the RSA Data Security. "RC" stands for the "Ron's Code" or the "Rivest's Cipher." It is quicker than DES and is intended as a "drop-in" replacement for the DES. It can be made safer or less safe than DES against exhaustive key search through using appropriate key sizes. It has the block size of 64 bits and is about two to three times quicker than DES in software. The algorithm is confidential as well as proprietary to RSA Data Security. RC2 can be employed in same modes as DES.