XTEA2 Block cipher encryption source code in C. eXtended TEA version 2. eXtended Tiny Encryption Algorithm 2.
XTEA2 was released in 2006. It has exactly the same design but uses 64-bit integers instead of 32-bit integers.
It no longer works on 64-bit blocks but on 128-bit blocks like AES and with 256-bit keys.