I am a graphic design student and for my information graphic project I have chosen the topic of the history of encryption and how the security level developed over the centuries. It’s basically an information graphic to make people like me aware of encryption and its importance in times like these (see: news about the NSA et al.).
So I'm taking several encryption concepts like the Caesar cipher, the Jefferson Wheel and something more modern like AES to calculate the Brute-Force time of the maximum key size. The main point is that I want to show that the security level grew enormously and in which size they grew.
Now the problem:
I wanted to calculate the key size, so I did research on the key sizes of each specific encryption concepts. In addition to that, I wanted to calculate the brute force time of an attack for each encryption (to find out how long it takes to crack the individual encryption). I know, that is a simple approach but I wanted to keep it simple as possible.
Now I’m not sure if I calculated it correctly and I would really appreciate it if someone could explain what I did not understand about that.
The brute-force computer I found (www.orange.co.jp/~masaki/rc572/ratej.php) was 2096204400 keys/sec and it is set up like 1 brute-force PC vs. an PC which is using this specific encryption.
Everything was calculated with wolframalpha.com
It got 25 possible combinations of characters (Wikipedia says its about 5bit) so that means the time
25/2096204400 seconds = 11.93 ns
Wikipedia says it’s roughly about 77Bit long, so the possible keys are 20651321783174268000000 and
206651321783174268000000 keys/2096204400 (keys/s) = 3.124×10^6average Gregorian years.
Are my calculations correct?