First outputs probabilities




Frequencies of occurrence of each of the possible 2^8 values on each
of the first 256 bytepositions of the keystream generated by the VMPC Stream Cipher were measured.
[In "A Practical Attack on Broadcast RC4" Itsik Mantin and Adi Shamir show that
the second output of RC4 takes on value 0 with probability 1/128 instead of 1/256.]
A test of 2^40.3 bytes generated by the VMPC Stream Cipher for 2^32.3 different keys
showed that each of the possible 256 values on each of the
first 256 positions is taken on with probability statistically insignificantly different from
the expected 1 / 256.
by Bartosz Zoltak

