Ciphers and codes are cool and fun (as is doing arithmetic on paper; I did that too, and sometimes still do LOL). Here is a link that details a number of well-known ciphers that remain unsolved after many years (in some cases, centuries), as well as some that were finally cracked:
http://www.elonka.com/UnsolvedCodes.html
Some of them are very interesting.
why even numbers are better
by John Doe 40 Replies latest jw friends
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