Synchronous stream ciphers produce long keystreams to be XORed with plaintext. The
output keystreams should be indistinguishable from truly random sequences and should not
leak any information about the secret key and the internal state of the cipher. In this study,
we propose six new statistical tests to evaluate the randomness properties of synchronous
stream ciphers. We applied four of these tests to the ciphers presented to ECRYPT and
tabulated the results.

Synchronous stream ciphers constitute an important class of symmetric ciphers. After the call
of the eSTREAM project in 2004, 34 stream ciphers with different design approaches were
proposed. In this thesis, we aim to provide a general framework to analyze stream ciphers
statistically. Firstly, we consider stream ciphers as pseudo random number generators and
study the quality of their output. We propose three randomness tests based on one
dimensional random walks. Moreover, we theoretically and experimentally analyze the …