We demonstrate that the public key cryptosystem based on the word problem on the Grigorchuk groups, as proposed by M. Garzon and Y. Zalcstein, is insecure. We do this by exploiting information contained in the public key in order to construct a key which behaves like the private key and allows successful decryption of ciphertexts. Before presenting our attack, we briefly describe the Grigorchuk groups and the proposed cryptosystem.
展开▼
