Hi Alex,
Yes, but it depends on how literally you mean with pen and paper.

I solved it without writing a program, but with Excel, several online tools (among others a transposition tool which revealed some plaintext) and finally indeed…

Now this was an especially fun one, but I wonder if someone actually solved this with pen & paper :-)

Alex.

One question: The challenge description says:

The plaintext of part 2 consists of 100 letters which means that each strip in the frame is used four times.

However, I have a total of 100 strips. Does that implicitly mean that only 25 of the s…

Indistinguishable characters "l" (small "L") and "I" (big "i") in the font used in PDF are another source of mistakes especially for users that solve the challenge manually.

is a good example which solved that problem elegantly.

About the ch…

OK, never mind, I just learned that the factorization method I'm using is magically calling up factordb - I was really wondering why it was that fast.

Although it this challenge wouldn't give any points, I tried to factor it nonetheless and was surprised, that the factorization took less than 2 seconds (!) on my machine. I wonder if it was deliberately that easy?

Ok, the challenge is nine year…

Hi everyone,

I'm now here for a few weeks and had quite a lot of fun so far.

I'm also really interested in how people solved problems, exploring their methods and discuss about tool chains in use. I just recently solved one challenge in what …

OK, I really liked this one, but it has one small evil twist which led me in the wrong direction :-)

Thanks a lot,
Alex.

Just to get this straight, we're talking about a vanilla-flavoured Pigpen as described in the Wikipedia article:

[img]https://upload.wikimedia.org/wikipedia/commons/thumb/3/36/Pigpen_cipher_key.svg/230px-Pigpen_cipher_key.svg.png[/img]

Also, j…

I felt like an alien trying to decipher the Arecibo message!
That was fun :-)

Oh gosh, now my eyes hurt! :-)
Good one! :-)

Alright, in the first 5 or 6 tries I did it wrong for problem 1 as I forgot that the Fib-sequence starts with 0,1,1 - not 1,1,2. Doh. it's even written in the example.

But now that I think I did it right, I'm stuck with the minimum period as some…

That was a fun one! I really enjoyed it :-)

Alex.

Hallo,

ich glaube, alles richtig gemacht zu haben, aber keine Antwort wird akzeptiert.

1. Habe das 'Keyword' gefunden, daraus ein Alphabet gebaut, und den Ciphertext damit verschluesselt, und bekam Plaintext.
2. In diesem Plaintext fand ich auch …

Hello everyone,

I'm new here and I just solved this challenge programmatically. Yes, you can determine the permutation for plaintexts of arbitrary lengths. I developed an algorithm to determine the permutation for a sequence of given length, thou…