Impossible Differential Cryptanalysis of Reduced Round XTEA and TEA
- Cite this paper as:
- Moon D., Hwang K., Lee W., Lee S., Lim J. (2002) Impossible Differential Cryptanalysis of Reduced Round XTEA and TEA. In: Daemen J., Rijmen V. (eds) Fast Software Encryption. FSE 2002. Lecture Notes in Computer Science, vol 2365. Springer, Berlin, Heidelberg
We present the impossible differential cryptanalysis of the block cipher XTEA and TEA. The core of the design principle of these block ciphers is an easy implementation and a simplicity. But this simplicity dose not offer a large diffusion property. Our impossible differential cryptanalysis of reduced-round versions of XTEA and TEA is based on this fact. We will show how to construct a 12-round impossible characteristic of XTEA. We can then derive 128-bit user key of the 14-round XTEA with 262.5 chosen plaintexts and 285 encryption times using the 12-round impossible characteristic. In addition, we will show how to construct a 10-round impossible characteristic of TEA. Then we can derive 128-bit user key of the 11-round TEA with 252.5 chosen plaintexts and 284 encryption times using the 10-round impossible characteristic.