Re: [ELPA] New package: vigenere

[Uwe Brauer <oub@mat.ucm.es>]

>>> "Ian" == Ian Dunn <dunni@gnu.org> writes:

   RMS> Please add text to the doc string saying,

   RMS> This is for historical interest, not a serious system for encryption.

   RMS> You might think everyone knows that, but most people are not curious
   RMS> about ciphers.

   > Done. I often find packages through their functions, so I added a note
   > about it to the function doc strings and the package commentary, for
   > good measure.

If I am not mistaken a Vigenere cipher is secure, if

    -  the key is as long as the message

    -  the key will only be used once

    -  the key is a random sequence

I am not entirely sure, but maybe this was the first implementation of a
one time pad.

BTW I think historically the autokey cipher, (the secret text is
added to the secret key) was also introduced by Vigenere. Maybe you
could add feature for historical reasons?

Uwe Brauer