A guest post by BOSS alumnus, upsidedown
This year marks my tenth Cipher Challenge (including the 2020 special
edition). Apart from the excitement of the main ciphers, I always look
forward to the lovely community on the forum: we share hints, help each
other out and devise ciphers and puzzles for each other to solve.
Now, in the course of setting & solving puzzles, it’s nice to post on
the forum to prove you’ve got the solution. Ideally, without revealing
your answer to everyone else! In 2020, Madness proposed using a one-way
function called MD5 as a proof method (for the cryptographers and
computer scientists: a hash function). It outputs a long, random-looking
sequence of numbers: anyone with the puzzle solution can reproduce the
same numbers, but it’s really difficult to work back from those numbers
to the solution. Perfect.
The Cipher Challenge team were kind enough this year to add a
Puzzle Proof Generator tool to make this easier. Just open the
webpage in your browser, fill in the details, then press the “Generate
proof” button. You’ll get something like the following, which you can
post on the forum:
PROOFv1:e88c1923b4cf0a46f856a0afe9814b8051ebd392b0970b8a6f623728ddbc8dc2
This not only proves that you’ve got the answer, but is unique to your
username: someone else would need the solution to generate their own
proof. See the Puzzle Proof Generator page for more details. And if you’ve got an idea for a
puzzle or cipher, however easy or difficult, go ahead and share it with
everyone on the forum!