The Tiny Encryption Algorithm, or TEA, is a public domain block cipher by David Wheeler and Roger Needham. It is intended for use in applications where code size is at a premium, or where it is necessary for someone to remember the algorithm and code it on an arbitrary machine at a later time.
This algorithm is simple enough to be translated into a number of different languages and assembly languages very easily. It is short enough to be programmed from memory or a copy.
The XTea is successor of Tea, modified for avoiding some weaknesses of original Tea algorithm.