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Questions tagged [history]

History of cryptography and cryptanalysis. Questions that wish to ask about the history of cryptography should use this tag; if you're asking about historical ciphers you may also wish to use the classical-cipher tag.

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What motivated the creation of RSA and ECDH?

Recently I've been learning about cryptography and so far I am loving it. However, there are some things I do not comprehend. As far as I know, RSA was published in 1979 while New Directions on ...
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0answers
95 views

Old French Cipher w/ Text Hidden In Drawing

I'm trying to find a cipher challenge I saw a few years back, it was an old drawing (I think 1800's or earlier) with clouds and stars on it and French text was hidden in the image. Does anyone happen ...
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1answer
860 views

In the RSA DES challenges, how did the contestants know they had found the right key considering they weren't given any plaintext?

If the contestants were given both the plaintext and ciphertext, it's straightforward. Just bruteforce all 56-bit keys until you find one that maps the given plaintext to the given ciphertext. But ...
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1answer
62 views

Question from WW2

I have seen in the imitation game that the Germans reset the Enigma, midnight sharp and then start messaging by sending the weather report morning. But the device by Alan Turing, took a few minutes ...
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2answers
651 views

Is RSA inspired by Diffie Hellman?

I read a bit of A Method for Obtaining Digital Signatures and Public-Key Cryptosystems that introduced RSA in 1977, and, while learning the steps in RSA a few days ago, I noticed that they are similar ...
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1answer
317 views

Who said “32 round Rijndael” in the third AES Conference

This is a historical question. In the third AES Conference of NIST (AES3), April 13-14, 2000, New York, near the end of the conference, one representative for each of the last 5 candidates sit on a ...
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1answer
93 views

Cryptanalysis in the middle ages — publications

Are there any publications, articles or literature discussing cryptanalysis and crypt breaking techniques in the middle-ages? I have seen various manuals from the middle ages describing various types ...
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3answers
247 views

Where can I find the description of SHA0 algorithm?

Where may I find the description and or pseudocode for the SHA0 algorithm. I am looking for something on these lines - HMAC RIPEMD. I have been implementing a few of those (HMAC, HOTP, TOTP and MD4, ...
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0answers
240 views

ECDSA public key recovery is discovered by whom?

Im looking for the history of the method (ECDSA public key recovery from signature). Where is this implementation first appeared in (is it bitcoin?) and who discovered this method?
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78 views

aside from DES has the NSA ever strengthened algorithms?

When DES was originally developed, the NSA changed the s-boxes. For decades people thought that their changes introduced a backdoor but then it was discovered that their changes actually strengthened ...
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5answers
10k views

How come Public key cryptography wasn't discovered earlier?

I became interested in crypto lately and read about symmetric and public key crypto algorithms. I understand how crucial the discoveries of the 1970s like RSA, DES and DH were in advancing the ...
2
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1answer
51 views

Would it be possible to negotiate a key of 128 or 256 bits strength using Merkle puzzles?

One can be fascinated by the simplicity of the schemes created by Ralf Merkle; like the Merkle tree or his key negociation protocol over an insecure channel. Wikipedia has some material on "Merkle ...
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Why is XOR preferred over XNOR in cryptography? [duplicate]

The advantages and properties exhibited by XOR are also exhibited by XNOR, like the ones mentioned in many answers like this one Information is preserved. $c = a \oplus b$. One may recover $a = c \...
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2answers
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Why did Histiaeus tattoo his slave's head?

The story is often told that Histiaeus tattooed a secret message on his slave's head, waited for his hair to grow back, then sent him off to Miletus. Why would he have done this? The story is usually ...
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1answer
2k views

What was the first hash and what problem was it supposed to solve?

Today's hashes have many uses. File integrity, verification of a secret without revealing the secret (i.e. passwords), hash maps, bloom filters, and probably a few more cases not immediately coming to ...
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1answer
142 views

Major Block Ciphers between DES and AES competitions

DES was announced as a standard in 1976. AES competition started in 1997 and Rijndael was selected as standard in 2000. What are major block ciphers and block cipher designs made/proposed from 1976 to ...
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2answers
336 views

How were one-time pads and keys historically generated?

In the 20th century, it was common for various intelligence agencies and military organizations to use ciphering machines and one-time pads. However, no source I've seen ever mentions the process of ...
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0answers
189 views

How did the cryptographers of Bletchley Park figured out the chi stream of the Lorenz cipher?

How did the Bletchy Park code breakers figured out the chi stream of the Lorenz cipher, that was obscured in the cipher text, which Britain code breakers eventually decoded. It's written in The ...
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1answer
73 views

How effective noise based voice encryption against attack?

In WWII the primary way of encrypting radio broadcasts was to have the broadcaster transmit a signal with noise added from record, while the receiver would have an identical copy of the record ...
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1answer
157 views

When was a RSA Private Key Introduced?

I'm doing some research into the RSA cryptosystem but I just need some clarity on how it worked when it was published in the 70s. Now I know that it works with public keys but did it also work with ...
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3answers
572 views

An unbreakable book cipher?

In a recent press interview, a former terrorist of the 1970s described the cipher his group used to communicate. He claimed that method was unbreakable and I wonder if cryptographers today would agree....
5
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1answer
185 views

How did “Secure Voice” work on the old Air Force One's?

I recently visited the "Museum of Flight" where they have an old SAM 970, previously known as "Air Force One". Inside there is a comm station with many buttons designated "Secure Voice", as can be ...
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1answer
510 views

Who issued the first SSL certificate?

When SSL was introduced in ~1996, there was only a few CAs issuing certificates for that specific use and a few sites which actually used SSL. Which Certification Authority issued the first SSL ...
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2answers
161 views

Steganography in speech by adding extra “filler” syllables [closed]

PREAMBLE About 20 years ago, when reading a novel (set in late 1800) by some classic Russian writer I came across very curious example of steganography. The two main characters were peasants who got ...
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2answers
603 views

Major code breaks in history

What are the major code breaks in the history of cryptography? Which code breaks changed the face of a battle or another major event? Which one had nationwide consequences?
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304 views

Have affine ciphers actually been used in practice?

I have been been studying some basic ciphers, and learnt about the affine cipher where the encryption function is given by $ax+b \pmod{26}$ for an alphabet with 26 characters. This is a very insecure ...
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1answer
60 views

How does Fialka manage to have a letter encipher unto itself?

http://www.cryptomuseum.com/crypto/fialka/index.htm Fialka was an electromechanical rotor machine. How does it manage to have a letter encipher unto itself. I realize it does something clever by ...
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1answer
207 views

Time gap between Diffie-Hellman Key Exchange and ElGamal encryption?

I'm looking into the Diffie-Hellman key exchange paper (New Directions in Cryptography, 1976) as part of a series of classic papers in Cryptography for my Ph.D and I was wondering if someone could ...
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1answer
96 views

Has the Linear Congruent Generator ever been used in any of the early crypto algorithms?

The Linear Congruent random number generator is the simplest kind of pseudo random number generator. I know that its now long broken. But I am curious -- has it ever been used in any of the early ...
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6answers
4k views

Did a certain cryptography method get abandoned due to security flaws in the past?

I am researching how quantum computers affect current encryption methods (RSA and more). However, I remember learning in a course that there used to be a particular encryption method which was ...
29
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1answer
4k views

Examples of modern, widely used ciphers that suddenly fell?

RC4 and GOST are two major ciphers (defined as being widely used to encrypt large amounts of data) that fell to cryptanalysis (relatively) suddenly. The first becoming totally broken and the second ...
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3answers
454 views

Turing's (still?) classified inference engine algorithm?

Does anyone know the algorithm used by Turing's Colossus inference engine, so highly classified that the Brits kept it secret for decades after WW II? Indeed, it may still be classified. Several ...
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2answers
5k views

Purpose of DES parity bits

DES has a 64-bit key size, but only 56 of those are used during encryption. The other 8 are "parity bits". What was the intended purpose of the party bits, and why are they no longer used in modern ...
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1answer
95 views

VIC cipher author known?

Does anybody know if the design of VIC cipher is attributed to anybody? I've tried Google and found nothing. There are quite a few sites describing the method in detail, a few implementing it ...
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2answers
428 views

Best non-digital cipher?

Is there an undisputed cipher that was considered the best before the computer age? (This is not suppose to be a discussion, it's either a yes or no.) Please give a brief description why it is yes ...
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1answer
129 views

Historical algorithm which is frequency analysis resilient

Long ago, I've read an article on wikipedia which describe a cipher algorithm, used by kgb (if I remember well) with the property that all ciphered letters has the same (or nearly) probability to ...
4
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1answer
271 views

Would the rotors in Enigma machines always advance by one position? Or was there a way to set this?

Before encrypting a letter the first rotor advances by one, right? So there could be a way, once the first rotor turns 26 times, make the second rotor advance two positions instead of one. Or three. ...
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3answers
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Why was the Navajo code not broken by the Japanese in WWII?

In reading about this topic recently, to my understanding, the encryption schemes used on top of the Navajo language were very simple and definitely could have been broken (my research shows they ...
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2answers
203 views

Historic Authentication Schemes Before Computers

The Bulletin of the Atomic Scientists recently ran an article about an alleged near miss with rockets in 1962, which raises some interesting cryptographic questions: After the usual time-check and ...
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2answers
133 views

How were semagrams encrypted in the pre-digital era?

Historically messages in languages that use alphabets have been encrypted manually according to some kind of algorithm (e.g. mono- and poly-alphabetic ciphers). But how wew messages encrypted in a ...
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1answer
642 views

When did Kerckhoffs's principle become fully accepted in design and practice of modern ciphers?

Kerckhoffs's principle is named after a publication over 130 years old. Yet it is still something that is commonly misunderstood and challenged by newcomers to cryptography. This question from Open ...
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What was the first MD5 collision ever constructed?

We all know that MD5's collision resistance is severly broken. But when thinking of "random" strings with great cryptographic importance I've come up with NIST's curve seeds and MD5 collisions. But ...
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234 views

How did G.H. Hardy's work contribute to today's public-key cryptography?

I know that Hardy's work in number theory was used by Clifford Cocks in 1973 to develop the basis for public-key cryptography. What specifically was this work, and how is it used today in ...
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4answers
162 views

Definition of the term “key”

I've looked in many places (NIST, text books, online resources) and I cannot find an answer to the definition of the term "key" from a semantic point of view. Is it the "key" to cipher-texts (i.e. ...
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1answer
186 views

Is the idea of a known plaintext attack really that new?

As you can probably guess, I just watched The Imitation Game, which hasn't really gotten points for historical accuracy... During World War II, Turing and his team fret that they can't know the ...
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1answer
641 views

Verbatim of early work on public-key cryptography?

In late 1997, the history of public-key cryptography was turned around with the announcement (then extended) that public-key cryptography was theorized in a 1970 note [1] by James Henry Ellis: The ...
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1answer
240 views

Engima machine decoding with PC and GPU

I saw this answer at this site about decoding a 3-rotor Engima machine's settings: How cryptographically secure was the original WW2 Enigma machine, from a modern viewpoint? And did some math for ...
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1answer
310 views

RSA was rejected by which journal?

Is it true that first time RSA algorithm was rejected by a journal?
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1answer
140 views

Is it possible to track down copies of WW2-era codebooks?

I've got an academic curiosity regarding some of the old Japanese naval codes used during World War II specifically. I'm wondering if any of the codebooks from this era have been made available, or ...
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How has the “power” of cryptography evolved from its beginnings till today? [closed]

I'm looking for a historical overview for the change in cryptographic power, which I hereby define as How far state-of-the-art cryptography is ahead of state-of-the-art cryptanalysis. In other ...