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Famous cryptographers’ tombstone cryptogram decrypted

nakedsecurity.sophos.com

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Re: Famous cryptographers’ tombstone cryptogram decrypted

#11

Post by excalibur »

At first glance, having no information on this other than a title and an image, I assumed there was some data encoded in the odd pattern on the flags at the top of the tombstone. I then read through the article waiting to learn what was there, and of course it was never mentioned.

A google search turned up a higher-resolution photo of the tombstone: http://elonka.com/friedman/Tombstone.JPG

The lines on the flags appear to be ordinary stripes, with nothing encoded in them. So I guess I can thank my own imagination for turning an otherwise fascinating story into a bit of a disappointment.

Re: Famous cryptographers’ tombstone cryptogram decrypted

#12

Post by zerocrates »

excalibur wrote: post #11

At first glance, having no information on this other than a title and an image, I assumed there was some data encoded in the odd pattern on the flags at the top of the tombstone. I then read through the article waiting to learn what was there, and of course it was never mentioned. A google search turned up a higher-resolution photo of the tombstone: http://elonka.com/friedman/Tombstone.JPG The lines on the flags appe…

Two flags crossing a torch is the insignia of the U.S. Army Signal Corps. The stripes here stand in for the areas of the flags that are red in the insignia.

Re: Famous cryptographers’ tombstone cryptogram decrypted

#13

Post by tlrobinson »

ythn wrote: post #10
logfromblammo wrote: post #7

Earlier quoted context omitted.

It's splitting hairs to make a distinction, but a cipher has an intended recipient and potential eavesdroppers, whereas a puzzle has no known recipient other than the potential eavesdroppers. A good cipher has to be readable by the intended recipient, and not by eavesdroppers, whereas a good puzzle cannot be impossible to crack. In that sense, DRM is a sort of anti-puzzle, as the intended recipients are treated as th…

> whereas a good puzzle cannot be impossible to crack. This is a very important distinction. It would be no fun if the cipher on a given cryptographer's tombstone were created with a one-time pad.

Well, a certain type of person would find it fun to put an unsolvable puzzle on their own tombstone.

Re: Famous cryptographers’ tombstone cryptogram decrypted

#14

Post by eries »

durkie wrote: post #6

also, a book just came out about Elizebeth Friedman and how a lot of her contributions to cryptology and the birth of sigint in general have been erased from histroy: https://www.amazon.com/Woman-Who-Smashed-Codes-Outwitted-ebo... it's supposed to be very good, but I just started it last night so don't have much of an opinion yet.

Confirmed, it’s great

Re: Famous cryptographers’ tombstone cryptogram decrypted

#16

Post by tptacek »

ChuckMcM wrote: post #5
tptacek wrote: post #2

My nit here would be that these things aren't "ciphers" so much as they are "puzzles".

How do you get there? You have a message text and you have a cipher text and you have an algorithm to go from one to the other. Seems like a cipher to me.

A decent threshold test is Kerckhoffs's principle.

Re: Famous cryptographers’ tombstone cryptogram decrypted

#17

Post by tptacek »

ChuckMcM wrote: post #8
logfromblammo wrote: post #7

Earlier quoted context omitted.

It's splitting hairs to make a distinction, but a cipher has an intended recipient and potential eavesdroppers, whereas a puzzle has no known recipient other than the potential eavesdroppers. A good cipher has to be readable by the intended recipient, and not by eavesdroppers, whereas a good puzzle cannot be impossible to crack. In that sense, DRM is a sort of anti-puzzle, as the intended recipients are treated as th…

Okay. I would expect that the message was sent by Willaim after he died to people who knew him. A sort of inside joke, that people like me, seeing his tombstone would completely miss. That said, I could see one making the case that it is steganography. I don't think 'good' and 'bad' really come into play, a caesar cipher is still a caesar cipher even if it is pretty easy to crack. But when you see it, it doesn't look…

Ideally, it should be "cryptographically" difficult to distinguish a steganographically-encoded message from an ordinary (noisy) encoding. The comparison between these kinds of cryptograms and steganography does about as much violence to the concept of steganography as it does to the concept of cryptography.

Re: Famous cryptographers’ tombstone cryptogram decrypted

#18

Post by ChrisSD »

ythn wrote: post #10
logfromblammo wrote: post #7

Earlier quoted context omitted.

It's splitting hairs to make a distinction, but a cipher has an intended recipient and potential eavesdroppers, whereas a puzzle has no known recipient other than the potential eavesdroppers. A good cipher has to be readable by the intended recipient, and not by eavesdroppers, whereas a good puzzle cannot be impossible to crack. In that sense, DRM is a sort of anti-puzzle, as the intended recipients are treated as th…

> whereas a good puzzle cannot be impossible to crack. This is a very important distinction. It would be no fun if the cipher on a given cryptographer's tombstone were created with a one-time pad.

Interestingly a one time pad may be crackable. Its theoretical uncrackability is only true if a truly random number generator is used. Most cryptography is fine with urandom but a one time pad requires using something like radioactive decay to generate your pad.

This is one reason (among many) why it's impractical for most crypto purposes.

Re: Famous cryptographers’ tombstone cryptogram decrypted

#19

Post by ChuckMcM »

tptacek wrote: post #16
ChuckMcM wrote: post #5

Earlier quoted context omitted.

How do you get there? You have a message text and you have a cipher text and you have an algorithm to go from one to the other. Seems like a cipher to me.

A decent threshold test is Kerckhoffs's principle.

Okay, read up on Kerckhoff.

I realize that when I talk about ciphers I don't distinguish between those which are easily reversed and those which are difficult to reverse. Kerckhoff was really concerned with cryptographic systems as a whole but his first principle that "The system must be practically, if not mathematically, indecipherable." would seem to be a function of the environment and the adversary.

To illustrate my thinking, I consider the mechanism on a Hallmark Diary cover that prevents you from opening it without the 'key' just as much a "lock" as the mechanism on the file cabinet that keeps secret material secret.

Given that, would my understanding be correct that any information obscuring or access preventing device which is susceptible to a 'lay person' inverting it, is, in your definition of things, a puzzle?

If that is correct, is the caesar cipher also a puzzle?

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