On the Applicability of Distinguishing Attacks Against Stream Ciphers

We demonstrate that the existence of distinguishing attacks against stream ciphers is unrelated to their security in practical use, and in particular that the amount of data required to perform a distinguishing attack is unrelated to the key length of the cipher. The implication for the NESSIE Project is that no submitted symmetric cipher would be accepted under the unpublished rules for distinguishing attacks, not even the block ciphers in Counter Mode or Out-