Cryptography

[kuiperbelt]

Anyone decipher this:

ELDSR ULR WSRH L WQQEWE MR HJG ZJ FVRE LVQ RRSO

[kuiperbelt]

oops, the key is 'LEMONS'

Hint: Bellaso

[TheWinner]

Three can keep a secret if two of them are dead.

[barry1010]

So Q, S and R are E? I don't get it, can you explain, Winner?

[barry1010]

Is it also an anagram?

[ZebuSanctuary]

By application of the Vigenere (decipher) method, the phrase as posted by 'TheWinner' is yielded.

For your edification;

The Vigenere cipher is a variant of the Bellaso cipher, but it was not derived from Bellaso's work.

It is important to recognize the individual achievements of both these figures in the field of cryptography. While they both worked on similar encryption techniques, they did so independently of each other.

[TheWinner]

I tried to do it the long way and got nowhere, so no credit to me, I used an online code solver.

[barry1010]

I am none the wiser, I still have no idea about this.

[Old_Geezer]

I guess you have to look up details of the Bellaso cypher, which presumably uses a code word ("lemons" in this case) in order to scramble the letters.

[TheWinner]

barry, I googledBellaso, he was an italian cryptologist. The Vigenère cipher is named after Blaise de Vigenère, although Giovan Battista Bellaso had invented it. I then found a site that decrypts messages using this system and entered the given letters plus the key word of "Lemons".

https://www.boxentriq.com/code-breaking/vigenere-cipher

[ZebuSanctuary]

>16:43

I implemented the Vigenere square which takes considerably longer.

Click on the link below;

https://ibb.co/nc5m9CC

By spelling out the key word LEMONS along the vertical axis and matching those letters to the corresponding letters of the desired message (to be sent) along the horizontal axis you obtain the cipher. Carry out the reverse operation to decrypt.

eg. Converting the first word 'THREE' into code.

L (vert axis) --- T (Horiz axis) results in the first letter E to be encrypted.

E --- H yields L
M --- R gives D
O --- E produces S
N --- E from the Square table R
S --- C (beginning of the next word) again from VSq generates U

... and so we start again with the letter L.

Hope this helps :-)

[barry1010]

Thanks all, it's a lot to take in

[TheWinner]

With the link I gave, you don't even need the keyword of Lemons.
Paste in the letters given: ELDSR ULR WSRH L WQQEWE MR HJG ZJ FVRE LVQ RRSO into the box and press enter. The solution shows straight away, no need to try and decipher any complicated tables.

[ClareTG0ld]

Codes can get complicated. In the end this is "just" a "shift cipher" but six different ones at once, but it is indeed tricky.

A rather interesting question is whether you could crack this one without knowing the keyword, or even its length. Hard to say, especially now that we're armed with that and the answer; I suspect there's not quite enough information.

[ClareTG0ld]

(for a human, that is -- or, at least, for me)