Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

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.

0
votes
1answer
59 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 ...
3
votes
2answers
629 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 ...
7
votes
1answer
297 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 ...
4
votes
1answer
92 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 ...
5
votes
3answers
205 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, ...
2
votes
0answers
203 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?
3
votes
0answers
65 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 ...
68
votes
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
votes
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 ...
3
votes
0answers
178 views

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 \...
10
votes
2answers
3k views

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 ...
19
votes
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 ...
5
votes
1answer
134 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 ...
11
votes
2answers
306 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 ...
5
votes
0answers
182 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 ...
2
votes
1answer
68 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 ...
0
votes
1answer
133 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 ...
2
votes
3answers
513 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
votes
1answer
180 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 ...
15
votes
1answer
467 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 ...
5
votes
2answers
153 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 ...
5
votes
2answers
599 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?
1
vote
0answers
257 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 ...
1
vote
1answer
56 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 ...
6
votes
1answer
203 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 ...
4
votes
1answer
93 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 ...
25
votes
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
votes
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 ...
14
votes
3answers
429 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 ...
14
votes
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 ...
5
votes
1answer
94 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 ...
1
vote
2answers
413 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 ...
1
vote
1answer
120 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
votes
1answer
265 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. ...
11
votes
3answers
2k views

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 ...
9
votes
2answers
202 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 ...
4
votes
2answers
129 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 ...
12
votes
1answer
633 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 ...
8
votes
3answers
918 views

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 ...
4
votes
0answers
220 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 ...
2
votes
4answers
154 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. ...
1
vote
1answer
177 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 ...
13
votes
1answer
623 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 ...
1
vote
1answer
233 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 ...
2
votes
1answer
306 views

RSA was rejected by which journal?

Is it true that first time RSA algorithm was rejected by a journal?
3
votes
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 ...
4
votes
0answers
132 views

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 ...
11
votes
1answer
231 views

What informal indicators exist for estimating the computational infeasibility of cryptographic problems?

When assuming a block cipher primitive is secure, or a number theoretic problem is hard, this assumption is usually based on how far we are from breaking the primitive or solving the problem using ...
25
votes
0answers
1k views

Who first published the interest of more than two prime factors in RSA?

Multi-prime RSA is now a well known technique (described here): it uses $k>2$ distinct secret prime factors in the public RSA modulus, with the advantage that, using the CRT, we can gain a speed ...
28
votes
3answers
20k views

How cryptographically secure was the original WW2 Enigma machine, from a modern viewpoint?

If cryptanalysts today were to crack the original Enigma machine, “how fast” or “how easily” could they do it? What methods would they use? The original cracking was significantly helped by operator ...