GCHQ Cracks Frank Sidebottom's Codes

#1

Post by rb2e » Sun, Apr 14, 2019, 12:53 AM UTC

GCHQ Cracks Frank Sidebottom's Codes
bbc.co.uk

Re: GCHQ Cracks Frank Sidebottom's Codes

#2

Post by bcherny » Sun, Apr 14, 2019, 1:26 AM UTC

Any more details on how the encoding worked? Was this just a substitution cypher with some gibberish sprinkled in?

Re: GCHQ Cracks Frank Sidebottom's Codes

#3

Post by LeoPanthera » Sun, Apr 14, 2019, 1:41 AM UTC

bcherny wrote: post #2

Any more details on how the encoding worked? Was this just a substitution cypher with some gibberish sprinkled in?

Since the article mentions finding duplicate symbols which corresponded to duplicate letters in words, it's probably a simple substitution cipher. Such codes can usually be broken with a combination of frequency analysis, and guesswork.

This one was apparently made more difficult by the fact that every other symbol was random. (And apparently using some symbols that did not otherwise appear in the code.)

Re: GCHQ Cracks Frank Sidebottom's Codes

#4

Post by brad0 » Sun, Apr 14, 2019, 1:42 AM UTC

bcherny wrote: post #2

Any more details on how the encoding worked? Was this just a substitution cypher with some gibberish sprinkled in?

Is gibberish called nulls or nonces? I forget.

Re: GCHQ Cracks Frank Sidebottom's Codes

#5

Post by Zenst » Sun, Apr 14, 2019, 1:48 AM UTC

bcherny wrote: post #2

Any more details on how the encoding worked? Was this just a substitution cypher with some gibberish sprinkled in?

Certainly seems that way. How I read "Noticing some repeated pairs of symbols - which represented letters - the first word cracked by GCHQ boffins was Sidebottom's favourite word, "bobbins"."

Though two triangles are used per letter - you can check that with one of the examples which has a message "Why does my nose hurt after concerts?" - 37 characters in total (including spaces), then count the triangles - 74. Hence two inside triangles are used per character.

But certainly highlights how adding noise to any encryption has it's upsides.

Re: GCHQ Cracks Frank Sidebottom's Codes

#6

Post by lainga » Sun, Apr 14, 2019, 1:52 AM UTC

brad0 wrote: post #4

bcherny wrote: post #2

Any more details on how the encoding worked? Was this just a substitution cypher with some gibberish sprinkled in?

Is gibberish called nulls or nonces? I forget.

Those are nulls. Nonces are random numbers for one-time-only use

Re: GCHQ Cracks Frank Sidebottom's Codes

#7

Post by paulgb » Sun, Apr 14, 2019, 2:04 AM UTC

If Frank Sidebottom is an unfamiliar name, I recommend the short audiobook Frank by Jon Ronson as an entertaining story. Jon played keyboards in his band and is an entertaining writer.

Re: GCHQ Cracks Frank Sidebottom's Codes

#8

Post by cortesoft » Sun, Apr 14, 2019, 2:10 AM UTC

brad0 wrote: post #4

bcherny wrote: post #2

Any more details on how the encoding worked? Was this just a substitution cypher with some gibberish sprinkled in?

Is gibberish called nulls or nonces? I forget.

Nonce is short for "number used only once"

Re: GCHQ Cracks Frank Sidebottom's Codes

#9

Post by kosievdmerwe » Sun, Apr 14, 2019, 2:13 AM UTC

lainga wrote: post #6

brad0 wrote: post #4

Earlier quoted context omitted.

Is gibberish called nulls or nonces? I forget.

Those are nulls. Nonces are random numbers for one-time-only use

Nonce contains "once", which makes it easier to remember.

Re: GCHQ Cracks Frank Sidebottom's Codes

#10

Post by ozzmotik » Sun, Apr 14, 2019, 2:19 AM UTC

paulgb wrote: post #7

If Frank Sidebottom is an unfamiliar name, I recommend the short audiobook Frank by Jon Ronson as an entertaining story. Jon played keyboards in his band and is an entertaining writer.

oh wow thanks for sharing that! I had never heard of frank but i definitely have heard of jon ronson from his research and look into psychopathy. oh and the men who stare at goats, of course. anyway i must now add yet another line to my ledger of things i really should be looking into