Re: a few questions about AES

<snip>
Not a hard limit, no, but there are only 2^128 possible blocks, so
after that much it is pretty sure to repeat itself, thus it would start
losing security. Due to the famous birthday phenomenon, on average it
will probably start repeating after only 2^64 blocks, which is 2^68
bytes or 295,147,905,179,352,825,856 bytes. For comparison, Google's
server farm only holds around 5,625,000,000,000,000 bytes, or about one
52,470th of that.
<end snip>

the reason why i asked these questions about AES is that i am trying to
assess the strength of my algorithm compared to AES.

i'm having a really hard time pinning down the strength of the algorithm. a
512 character string has 4096 bits in it, but according to my calculations
(not very good at exponent math) the possible combinations within those 4096
bits is something along the mark of 1.0443^1233 possible keys. seems a bit
high to me. i'm probably calculating it wrong... i mean REALLY wrong. i got
such a huge number from following
http://www.ciphersbyritter.com/LEARNING.HTM#ExKeyspace which essentially
states that for each byte you multiply by 256. the example it gave is an 8
bit cipher which is 256 keys, and a 16 bit cipher is 65536 keys (256 * 256).
after further modification of the algorithm i have caltulated that the key
will repeat itself after 15.25TB due to the method of key generation and a
further 4 different methods of permutation. again, it wouldnt suprise me if
i am off the mark.


.

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