June 19, 2011 6:21 pm at 6:21 pm #597483
In a different thread, an encrypted message was posted with the intent that only one other person would decipher it.
When people use homemade encryption keys, they will often share the key beforehand and then send a message using that key.
The longer the message, the more likely letter frequency, letter doubling, one, two and three letter words, and other patterns can be used to crack the code.
2) Write out the alphabet twice, i.e.
Once I reach the end of my key, I return to the first letter.June 19, 2011 8:07 pm at 8:07 pm #792507
I think I burst a blood vessel in my brain reading that post.June 19, 2011 9:08 pm at 9:08 pm #792508moishyParticipant
yeah me too.June 19, 2011 9:19 pm at 9:19 pm #792509ZeesKiteParticipant
I’m just encrypting my brain to be able to decipher how to encrypt the undecipherable encryption.June 19, 2011 9:33 pm at 9:33 pm #792510
Mother in Israel-
My original post contains an error.
“my second letter will be represented by 20.” should be “my third letter will be represented by 20.”June 19, 2011 9:37 pm at 9:37 pm #792511
My original post contains an error.
“my second letter will be represented by 20.” should be “my third letter will be represented by 20.”
Well, THAT explains it. Now it all makes sense. But of course.June 19, 2011 10:53 pm at 10:53 pm #792512minyan galMember
I often enjoy doing crytogram or crytoquote puzzles in the newspaper or in a crossword puzzle book, but this doesn’t seem to bear any resemblence to those puzzles.June 20, 2011 12:43 am at 12:43 am #792513SabziMember
if your already sharing a key, you may as well go for something cool like “Elliptic Curve Cryptography”June 20, 2011 1:49 am at 1:49 am #792514gefenParticipant
for all of you who had a hard time understanding that, u better go back to kindergarten – come on – this is baby stuff! (ya right!)
zeeskite – for a 9 yr. old, you have a pretty sophisticated vocabulary. very impressive.June 20, 2011 2:48 am at 2:48 am #792515
Mother in Israel–
This is pretty much the opposite of those puzzles, in that this is supposed to be unsolvable.
Ambitious idea, but no way!
Elliptic Curve, public and private key and other encryption methods I barely have a handle on are way beyond the scope of this thread.
I am simply trying to suggest a method for party “A” to securely exchange info with party “B” in a non-secure environment.June 20, 2011 4:56 am at 4:56 am #792516ZachKessinMember
The substitution cipher you describe is about 2000 years old. Julius Caesar used it.
During WWII the Nazis used a much enhanced version called Enigma that thankfully had a few critical flaws that enabled the Brits to break the code.
Modern codes are based on all sorts of complex math that is way over my head.June 20, 2011 5:55 am at 5:55 am #792517ZeesKiteParticipant
I took those words from a spelling test of my older sister, did some suffixing, and repeated them over and over. That’s all.June 20, 2011 8:04 am at 8:04 am #792518SabziMember
I can only try – you would still have to solve the issue of communicating the “shared key” in a non secure environment. classic cryptography issue, g’luckJune 20, 2011 12:46 pm at 12:46 pm #792519
The method described in the original post is basically the one-time pad (or one-time code pad) encryption technique. It’s very simple, but still pretty much unbreakable, simply because it’s variable and doesn’t provide a large enough sample to decipher. I guess you could say it’s similar to Enigma in that both use varying substitutions, but they’re really not at all the same – the Enigma was a mechanical device.
The stories of how Germany’s Enigma and Japan’s Purple were cracked are very interesting.
The effort to crack Enigma had two prongs – the Bletchley Park computers were working to decrypt it, and others were trying to capture a machine intact. Both groups succeeded. Polish codebreakers actually get the credit for first cracking Enigma.
U.S. codebreakers cracked Purple, but they kept this to themselves for a while, and let Japan go on thinking their encoded messages were secure. When the U.S. intercepted a message about a long flight that Isoroku Yamamato, Japans foremost military strategist and architect of the Pearl Harbor attack, would be aboard, it was time to finally tip their hand. A successful long-range intercept of his flight by P-38 fighters resulted in Yamamato’s plane being shot down, and Yamamato was killed.June 20, 2011 12:58 pm at 12:58 pm #792520HaLeiViParticipant
Zach, the main flaw was the fact that the allies got hold of it before the war started. They had to keep it a secret and even let soldiers die so as not to give the Germans reason to believe they were hacked.
Here’s another system. Open a large bitmap picture in a byte editor and replace every twelfth bytes with the byte of your letter.
Or get the byte values of your message, multiply them by a predestined number, encode it in base64, then multiply again, encode in utf8, and so on.June 20, 2011 1:37 pm at 1:37 pm #792521ZachKessinMember
Actually even after shooting down Adm. Yamamato’s aircraft I think Japan still didn’t know that their codes. The various efforts that the allies took to keep the axis from figuring it out that the codes had been broken was quite extensive.
The one time pad can be proven to be unbreakable as long as you can figure out how to distribute the keys to the people who need them. The problem is you need 1 bit of key for each bit of data you wish to encrypt.June 20, 2011 2:25 pm at 2:25 pm #792522
I can only try-
The advantage to the method you mentioned in your opening post is that it can be decoded by hand.
I read a story in an old book about the FBI from the mid 1950s (sorry if that makes you old) about a paper boy who got paid a Nickel that felt different. It turns out that it was hollow with the front and back being from two different years. Anyway, inside the nickel there was an encrypted message that the FBI couldn’t figure out. (They knew it was from the Soviets from the precision that the two halves fit together.)
When they finally got to the bottom of the case it turns out that it was encoded with a similar technique that you mentioned above.
Modern encryption nowadays uses mathematical functions that have no inverse function. Public Key/ Private Key methods uses prime numbers. While there are various methods to test the primality of a number, one will only know if it is prime or not, not what the factors are. One can easily take two long primes and multiply them together while it could take a hacker months or years to factor the product.
(The details on how this works is beyond the scope of this thread. If you are interested in a real life working example please let me know.)
Another method I used to use when I was younger is Matrix Encryption, and this can be done by hand. The way it works is an invertible 3 X 3 matrix is used to encode a message and the message is decoded by finding the inverse of the matrix and multiplying it by encoded message.
When my younger brother was in camp he mentioned that he thought it was nosy that the office staff would read the faxes that came in so he asked me to encode them. At the beginning of each fax I would tell him which matrix to use. He loved all the attention he was getting as his bunk would watch him meticulously decode the message claiming it was extremely sensitive information.
He had to leave camp a few days early that year so on his last day I send a fax that said “Urgent, Please deliver to Moshe Pepper Immediately.
Our Cipher has been compromised, abort mission immediately and leave camp at once… He got a kick out of it.June 20, 2011 3:11 pm at 3:11 pm #792523Busy As A BeeParticipant
That made me laugh Dr. Pepper.
Nice to see you posting again. I always enjoyed your stories ðŸ˜€June 20, 2011 4:54 pm at 4:54 pm #792524veteranMember
“The effort to crack Enigma had two prongs – the Bletchley Park computers were working to decrypt it, and others were trying to capture a machine intact. Both groups succeeded. Polish codebreakers actually get the credit for first cracking Enigma.”
The Polish codebreaking is an interesting story, and I believe (IMHO) it is also the origin of the term of “doing something the Polish way”.
Poland was anticipating an invasion by the Nazis and was therefore extremely motivated to crack their coded messages (more so than England and other countries who were also working on it at the time but were not in imminent danger of invasion yet). They set up teams to crack the Enigma code, and succeeded initially. The irony is that the supervisor of the code breaking team had a copy of the book containing the daily “keys” but did not let anyone know. He felt that if he let it be known that he had the code book the code breakers would not learn how to crack the code and he needed them to learn those skills just in case his spy stopped providing the keys.
Sure enough, the source dried up and breaking the Enigma code was only possible through the brute force method. Unfortunately, this happened at the same time that the Germans increased the difficulty of the Enigma encryption (out of paranoia) and the code breakers were unsuccessful from that point on.
(As told by Simon Singh)June 20, 2011 5:09 pm at 5:09 pm #792525
Years later a Soviet agent defected to the U.S. and turned over the spy behind the nickel and the key to decrypt it.
The Soviet spy went by the name Rudolph Abel, and he was sentenced to a long term in prison.
You may have heard of this American defector. His name was Lee Harvey Oswald.June 20, 2011 8:17 pm at 8:17 pm #792526
Urgent, Please deliver to Moshe Pepper Immediately.
Hey, I know Moshe Pepper! Is that your brother’s real name?June 20, 2011 8:22 pm at 8:22 pm #792527
Tell him his brother Avi sends his warmest regards.June 20, 2011 8:26 pm at 8:26 pm #792528
Avichai?June 20, 2011 8:35 pm at 8:35 pm #792529
Where would you know my brother from?June 20, 2011 9:16 pm at 9:16 pm #792530
The Moshe Pepper I know has an older brother Avichai, so I guess I don’t know your brother.June 21, 2011 3:45 pm at 3:45 pm #792532
Sorry to hear that, it’s your loss. He really is a fun guy to be around.
Just curious, is the one you know also a Kohen?June 21, 2011 7:11 pm at 7:11 pm #792533
I’m pretty sure he’s not.June 21, 2011 7:15 pm at 7:15 pm #792534
If that’s the case then he’s not even related.June 21, 2011 7:18 pm at 7:18 pm #792535
I do know Pfeffers who are kohanim though. Could that have been the same name once?June 21, 2011 7:24 pm at 7:24 pm #792536Pac-ManMember
I believe Doc mentioned Pfeffer was his family pre-immigration name.June 22, 2011 11:06 am at 11:06 am #792537
The book that you mentioned – “The Code Book” by Simon Singh – is one that I really enjoyed.
I’d recommend it for its technical information, its stories and historical information, and the easy, readable style in which it’s written.June 23, 2011 9:35 pm at 9:35 pm #792538
How did you remember that? Today is the tenth anniversary of that post!June 23, 2011 11:25 pm at 11:25 pm #792539Pac-ManMember
I happened to remember it. I think the better question is what made Mother in Israel think to associate Pepper to Pfeffer. I would tend to think it is somewhat rare that a Pfeffer became a Pepper at Ellis Island. But MiI says her Pfeffer’s are Kohanim, so the question at hand is what’s the relation.June 23, 2011 11:34 pm at 11:34 pm #792540
I think the better question is what made Mother in Israel think to associate Pepper to Pfeffer.
The Peppers that I know (Moshe, Avichai, et al) call themselves Pfeffer when they’re in Israel. That was what made me associate Pepper with Pfeffer.August 1, 2011 2:53 pm at 2:53 pm #792541
I can only try-
You may have heard of this American defector. His name was Lee Harvey Oswald.
34 years ago today Gary Powers got killed when the helicopter he was flying ran out of fuel.
(I remember that you like thing from “Today’s Date In History”.)August 1, 2011 6:16 pm at 6:16 pm #792542
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