Polygraphic Substitution - Cryptanalysis of General Polygraphic Substitutions

Cryptanalysis of General Polygraphic Substitutions

Polygraphic systems do provide a significant improvement in security over monoalphabetic substitutions. Given an individual letter 'E' in a message, it could be encrypted using any of 52 instructions depending on its location and neighbors, which can be used to great advantage to mask the frequency of individual letters. However, the security boost is limited; while it generally requires a larger sample of text to crack, it can still be done by hand.

Read more about this topic:  Polygraphic Substitution

Famous quotes containing the word general:

    We have seen over and over that white male historians in general have tended to dismiss any history they didn’t themselves write, on the grounds that it is unserious, unscholarly, a fad, too “political,” “merely” oral and thus unreliable.
    Adrienne Rich (b. 1929)