On Sunday, September 24, 2017, 3:25:10 PM PDT, \0xDynamite
   <dreamingforward@gmail.com> wrote:
   On 8/4/17, jim bell <[1]jdb10987@yahoo.com> wrote:
   >> "Vernam cipher"
   >YES!  That is the cipher.  I can't believe I forgot the name of it.
   Geez, I'm just re-realizing all of my undergrad training.
   >AFAICT, it is UNBREAKABLE if the keysize is at least half the size of
   your plaintext.
   >Marxos
   My understanding is that the keysize ought to be as long as the message
   to be encrypted.
   And yes, it is unbreakable...   UNLESS you try to reuse the keys!!!
   Google-search the word "Venona" to learn more.
                Jim Bell

References

   1. mailto:jdb10987@yahoo.com