We assume that the computer has a 3GHz processor.
Assume that the machine takes a 100 cycles per brute force substitution against a single 56-bit
Time required to crack a 56-bit key DES encryption ->
2^56 key * 100 cycles / 60 sec / 60 min / 24 hrs / 365 days / 3000000000Hz
=> 76.16438 years
Time required cracking a 128-bit key AES Encryption ->
Assume the machine takes a 100 cycles per brute force substitution against a single 128-bit AES
2^128 key * 100 cycles / 60 sec / 60 min / 24 hrs / 365 days / 3000000000Hz
According to Moore's Law ->
Processors double in power approximately every two years.
For a 128-bit AES encryption to be cracked in a week of processing ->
With a processor speed of 58,028,439,341,502,200,385.8968 Peta Hertz, a 128-bit AES
encryption could be cracked in approximately a week's time.
According to Moore's Law, it takes a total of 150 years from now.