Implications of bitsum attack on tiny Encryption Algorithm and XTEA

Abstract

TEA and XTEA are block ciphers that uses Fiestal structure. We enciphered a fixed message with different keys using TEA and XTEA cryptographic algorithms. Our interest was to find the correlation of the bitsum of the ciphertext with the bitsums of the corresponding keys. In our attempt, we found that for specific patterns of keys, whatever be the plaintext, the bitsum of the key is in perfect correlation with bitsum of the ciphertext.