# Challenge 7

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Viewing 15 posts - 46 through 60 (of 80 total)
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• #48335
Harry
Keymaster

For anyone still stuck on cracking the double encrypted 7B, think about it: what you would do if it was only single encrypted? What have you learned about cracking the two types of cipher that are used here? Combine those techniques and you should be able to crack this one!

Harry

#48334
Keymaster

I still can’t solve 7B. Anymore help?

#48331
Inactive

Harry is the title for Part B the keyword for translation? I have tried it as [….] but no possibilities work.

{It is your choice Harry to edit out what you think should not been shown}

[What keyword lengths are likely for this text and this type of cipher? Harry]

#48337
Inactive

Oh! Got the keyword now. Thanks Harry.

#48342
Keymaster

I feel like I have a keyword (only word in 7A with a certain length) and also 2 substitutions, but the keyword has so many repeated letters that there are so many different ways to arrange the text? The one clue that would really help me would be if I could work out what letter has replaced h…

#48341
Inactive

I think i have managed to solve 7B but i did not add the spaces in correctly, please could somebody give me a hint as to add the spaces in?

#48339
Keymaster

Technically, you don’t need a key word; you just need a key number and a key permutation.

#48347
Keymaster

is the length of the keyword a factor of the number of letters in the cyphertext?

[Excellent question!! Harry]

#48348
Keymaster

@Millermg You shouldn’t need to add any spaces in, the checking software removes all capitals, spaces punctuation etc. and just checks the actual text

#48350
Keymaster

I’m still clueless

[In general, or just with regards to Challenge 7? Harry]

#48351
Keymaster

In regards to 7B

#48352
Keymaster

Harry help

#48354
Keymaster

Harry, Challenge 7 is almost over so a direct hint would be very appreciated!

[It is only 2/3 over! Harry]

#48356
Inactive

Harry[/Hrarny!], – if anyone needs a few hints for 7B…

The breakthrough for me came when I looked at the opening 30 – 40 letters of the interim ciphertext (after deciphering the Caesar[/Casear!] shift), and considered what I knew about the nature/subject matter of the plaintext, from the plaintext of 7A, in terms of what words I might expect to see at the start of it. I also factorised the length of the ciphertext (excluding spaces and punctuation) to give me a clue as to the length of the keyword (i.e. the lengths of the “chunks” of the plaintext that were encrypted using the same transposition/permutation). After a bit of trial and error, I found a transposition that turned the interim ciphertext into the plaintext.

I can’t figure out the keyword though!

#48357