|
|
|
| Do you know where your variables are? | |
| PerlMonks |
Re: encryption (chi-squared test)by gumby (Scribe) |
| on Jun 20, 2002 at 12:40 UTC ( #175986=note: print w/replies, xml ) | Need Help?? |
|
An alternative, of course, is to use a statistical method: use the chi-squared test (see Mathworld). Let F_a(x) be the frequency of some letter, x, in you're alphabet, and let F_m(x) be the frequency of some letter, x, in the message. Now, for all 0 <= s <= 25 calculate for each letter, x, in your alphabet the sum of the squares of F_m((x + s)(mod 26)) / F_a(x). The value of s for which this obtains a minimum is the shift used to encipher the message.
In Section
Seekers of Perl Wisdom
|
|
||||||||||||||||||||||||