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.

Filter by
Sorted by
Tagged with
2 votes
1 answer
92 views

What was the DES Challenge III key?

When the Electronic Frontier Foundation and distributed.net broke the DES Challenge III in less than a day, revealing the message ...
JamesTheAwesomeDude's user avatar
1 vote
1 answer
203 views

What Happened to MD3 in Rivest's Series of Hash Functions?

Ronald Rivest designed MD2, MD4, MD5, and MD6, but what about MD3? Was it skipped? Or perhaps kept private and never publicly released? (edit: found a related question)
hanshenrik's user avatar
2 votes
2 answers
80 views

Who first applied hill climbing algorithms to cryptanalysis?

As you may know, classical ciphers are now often broken with hill-climbing algorithms. The earliest mention of them in cryptography I could find occurs in some 1980s publication mentioning 1979 PhD ...
ain92's user avatar
  • 121
4 votes
1 answer
96 views

"pc" variant of McEliece—what is it?

It looks like the IETF draft specification of Classic McEliece has penciled in separate variants of the algorithm for so-called "pc" and "non-pc" variants (as well as the familiar &...
JamesTheAwesomeDude's user avatar
7 votes
0 answers
237 views

Who invented salt, and why is it called salt?

I'm looking for an authoritative reference about the history of salts in the context of hash functions. Why is the personalization string in a hash function called a "salt"? Who should be ...
Mikero's user avatar
  • 13.2k
5 votes
1 answer
133 views

Cryptanalysis of the GOC

The GOC (Générateur d'Octets Chiffrants, Ciphering Byte Generator) is a PseudoRandom Generator that was used during the late 20th century for content encryption in pre-internet Videotex terminals, ...
fgrieu's user avatar
  • 141k
1 vote
0 answers
62 views

Authors of "How to explain zero-knowledge Protocols to your children?"

Does anyone know what are the family relationships in the paper "How to Explain Zero-Knowledge Protocols to Your Children" The authors are: Jean-Jacques Quisquater, Myriam Quisquater, Muriel ...
Alex Them's user avatar
2 votes
2 answers
71 views

DES initial key generation

I am working through a textbook on crypto, currently on DES section. What bothers me is that there was no explanation about where do we get initial 64-bit key from. This question is also very hard to ...
Michael Hammer's user avatar
1 vote
0 answers
82 views

Who developed SHA-2 family?

When I look up who developed SHA-2 family, the result I get is along the lines of SHA-2 was first published by the National Institute of Standards and Technology (NIST) as a U.S. federal standard. ...
Josh's user avatar
  • 135
5 votes
1 answer
683 views

Resistance against timing attacks of AES candidates

It's difficult to implement AES securely and efficiently if the adversary can observe the timing and (approximate) location of memory accesses, unless you have dedicated hardware. The naive ...
Gilles 'SO- stop being evil''s user avatar
6 votes
1 answer
757 views

Public-key authentication that is feasible by hand, before computers?

I wonder if it's possible to do public key authentication (preferably not vulnerable to replay attacks) before modern computers became a thing (e.g. in a medieval setting). Specifically: ...
Azuresonance's user avatar
0 votes
0 answers
95 views

CCA-Attacks in the real (and digital) world

Is any concrete and real examples of CCA-attacks in recent history. I'm aware about examples of WW2, but I'm more interested to modern examples in a digital context (for example against OFB, CBC).
Ievgeni's user avatar
  • 2,585
1 vote
1 answer
120 views

Other than in the UK, what famous mathematicians were involved in cryptology in WWII?

The famous names of mathematicians at Bletchley Park are now a matter of public record and include eminent figures such as Max Newman, JWS Cassels, Philip Hall and Sandy Green as well as the more ...
Daniel S's user avatar
  • 23.6k
2 votes
1 answer
70 views

Before Bitcoin what was the motivation for researching key aggregation multisig and threshold schemes?

The motivation for key aggregation multisig and threshold schemes (e.g. MuSig(2), FROST etc) in Bitcoin is obvious. Signatures are a large part of every transaction, all the nodes on the network are ...
Michael Folkson's user avatar
3 votes
0 answers
158 views

What are the concrete changes the NSA did to the algorithm before DES was published?

It's common knowledge that the NSA, before publication of DES, tweaked the algorithm to improve its resistance against differential cryptanalysis. Schneier writes some of this on his blog, for example ...
performancematters's user avatar
2 votes
1 answer
435 views

Mathematical definition of scytale

Most cryptographers know the scytale. It is that cipher where you roll a leather strip around a rod and then write text on it. For encryption you roll it off the stick and for decryption you roll it ...
Titanlord's user avatar
  • 2,244
2 votes
0 answers
147 views

How did the developers of SHA-2 algorithm come to what we have now?

After a bit of research, I finally understand what's the step by step algorithm of SHA-2 (however, of course, I won't remember it myself). But I don't understand what's the idea behind it. Did the ...
Wynell's user avatar
  • 121
27 votes
7 answers
5k views

Is there any famous protocol that were proven secure but whose proof was wrong and lead to real world attacks?

Are there moderns (post World War II) and famous protocols that were proven secure (in any model: game-based, UC...) but whose proof was wrong and could have led to real-world attacks? Note that: I'm ...
Léo Colisson's user avatar
33 votes
8 answers
12k views

Have any cryptographic breaks been executed in the real world since World War II?

Have there been any publicly known exploits of a cryptographic break in a widely used cryptographic system to actually read encrypted information (or falsely authenticate) since the Ultra program in ...
Very Tiny Brain's user avatar
5 votes
2 answers
187 views

Does machine cryptography only consist of rotor machines?

For the chronological categorisation of cryptography, I have proceeded as follows: Cryptography by hand (e.g. Caesar, Vigenére, etc., till around 1900/1920) Cryptography using machines (e.g. Enigma, ...
Titanlord's user avatar
  • 2,244
4 votes
1 answer
183 views

Encryption/Cryptographic techniques in financial documents (pre-1970s)

do you know anyone who works in finance/banking who knows about encryption of financial documents? This is for an academic research paper, whereby I would be interested to research further information ...
netad4's user avatar
  • 41
1 vote
1 answer
691 views

Where did affine cipher get its name from?

I was wondering where did affine cipher get its name from. I am curious to know its origin and how it is related to the cipher. The Affine Transformation page on Wikipedia states: In Euclidean ...
Josh's user avatar
  • 135
10 votes
1 answer
592 views

Who is the inventor of the OFB block cipher mode of operation?

Handbook of Applied Cryptography gives two resources for the OFB mode 1980 FIPS 81. This doesn't give any references, unlike NIST. 1983 ANSI X3.106, unfortunately pay-walled. Who is the inventor of ...
kelalaka's user avatar
  • 48.4k
8 votes
2 answers
301 views

Is possible to a implement AES in a electromechanical machine in the 1900?

Can AES be implemented in a electromechanical machine in early 20th century? Specifically does any machine from that era have the capability to implement byte-oriented S-Box, or to implement the ...
Wilhelm's user avatar
  • 81
6 votes
2 answers
425 views

What were Alan Turing and their team searching before doing KPA in the movie "The imitation game"?

I just watched the movie "The imitation game" (2014) which is based on Alan Turing's biography. At some point in the movie the machine built by Turing wasn't fast enough to decrypt the ...
melfnt's user avatar
  • 163
2 votes
1 answer
66 views

Early field use of digital signature

What are documented early field uses of digital signature? The oldest I found is reported by Charles H. Bennett, Gilles Brassard, Seth Breidbart, Stephen Wiesner's Quantum Cryptography, or Unforgeable ...
fgrieu's user avatar
  • 141k
11 votes
3 answers
4k views

Common Classical Ciphers

When studying cryptography, the first thing every student learns is some historical ciphers. There are way too many of those ciphers to name them all. So my question is: What are the most important ...
Titanlord's user avatar
  • 2,244
7 votes
1 answer
1k views

Opinion from "military institution" about the academic work

A few years ago, I've heard about a harsh report from an American institution (I've forgotten which one, but it was something like the NSA) about IACR conferences. Which report could it be? I think ...
Ievgeni's user avatar
  • 2,585
10 votes
2 answers
430 views

Notable Non-Western Cryptosystems that have been widely deployed?

I was recently watching Sneakers (which Len Adleman advised on their "cryptography" sub-plot), which included a line along the lines of: [Some hardware that ostensibly breaks American ...
Mark Schultz-Wu's user avatar
  • 12.9k
6 votes
2 answers
431 views

Examples of Weak Cryptography being exploited in the wild by cybercriminals?

As a theorist, I often motivate the need for strong cryptography via simplistic methods, such as "If this did not exist, your online bank transactions would be vulnerable". This is of course ...
Mark Schultz-Wu's user avatar
  • 12.9k
4 votes
1 answer
108 views

Did the formalization of PKCS#1 RSA key formats come before or after X.509?

The paper introducing the RSA cryptosystem titled "A Method for Obtaining Digital Signature and Public-Key Cryptosystems" was published in 1978. The initial version of X.500 published by ...
DannyNiu's user avatar
  • 9,207
3 votes
1 answer
66 views

Where is the "Letter to NBS, October 22, 1975"

Discussions of the weakness of the U.S. Data Encryption Standard frequently cite a letter by Martin Hellman and Whitfield Diffie to the National Bureau of Standards that reported stated: Whit Diffie ...
vy32's user avatar
  • 439
1 vote
0 answers
105 views

In my opinion a lot of encryption paper have small contribution in terms of security improvements [closed]

I used to saw a lot of encryption papers that have small significance in security improvements especially in terms of entropy, histogram and coefficient correlation especially in image encryption. Why ...
Codeboy Newbie's user avatar
0 votes
1 answer
110 views

What are the fundamental roots of modern symmetric encryption?

In academic pursuits, we often have people (and their ideas) who are considered fundamental to the subject, such as Bayes and probability. In cryptography, it's obvious to see that the Diffie-Hellman ...
Modal Nest's user avatar
  • 1,443
6 votes
3 answers
385 views

Would asymmetric cryptography be feasible in World War II?

Assuming people in the forties would have known asymmetric cryptographic methods like RSA, would they have been able to make sensible use of them? There were no real electronic computers at the time, ...
J Fabian Meier's user avatar
2 votes
1 answer
112 views

Why was it easier to decode messages that you had several copies of?

During WW1 the German ambassador in Washington, von Bernstorff, blamed their numerous transmissions of the same messages as the cause for the successful decoding done by the British. I don't see the ...
Kristian Francisco Milla Niels's user avatar
2 votes
2 answers
1k views

How were codes in WW1 reciphered (to enhance security levels) without them turning meaningless?

In WW1, the Germans made their communications secret by encoding their messages. This meant that the message's sender would have a codebook with all possible words and phrases he might use listed in ...
Kristian Francisco Milla Niels's user avatar
18 votes
1 answer
1k views

Crypto AG (Switzerland) - Which algorithms were used and how did the backdoors work?

Backstory Crypto AG was a company located in Switzerland that specialized in communication security. They produced a number of encryption machines (some similar to the infamous Enigma) used for ...
AleksanderCH's user avatar
  • 6,435
4 votes
0 answers
520 views

Security properties of ElGamal encryption variants

I'll use Taher ElGamal's A Public Key Cryptosystem and a Signature Scheme Based on Discrete Logarithms (July 1985 in IEEE Transactions on Information Theory, formerly in proceedings of Crypto 1984) as ...
fgrieu's user avatar
  • 141k
0 votes
1 answer
107 views

Side-channel attack in the real wold [duplicate]

I have a big problem to figure how the security model in papers about side-channel are relevant (briefly the attacker has a partial access to the hardware). Why these breaches are so seriously ...
Ievgeni's user avatar
  • 2,585
1 vote
0 answers
66 views

Are there official test vectors for historic ciphers? [closed]

In many cases when cryptographic algorithms are published the paper also provides a set of test vectors that can be used by developers to verify their implementations. For historic ciphers such as ...
766F6964's user avatar
  • 111
3 votes
4 answers
425 views

Academic breach revealed too late

Do you know if is has already happened (since 1980), that someone (academic or not) has "broken" (even in a weak sense) some cryptographic assumption, but has chosen to not first publish and directly ...
Ievgeni's user avatar
  • 2,585
3 votes
1 answer
210 views

Could public-key crypto be performed long ago if the idea had been discovered?

Public-key cryptography was not invented until the 1970's. Apart from the idea not existing earlier (as talked about here), is there any reason it could not have been used earlier? For example, are ...
Captain Man's user avatar
3 votes
3 answers
446 views

Most secure but feasible encryption running on WWII technology

Imagine you are transported back to ~1940. What is the best (i.e. most secure, but technologically feasible) encryption you can think of for widespread (i.e. military) use? How would you implement it?
3244611user's user avatar
3 votes
0 answers
94 views

What was used for symmetric message authentication before HMAC was invented?

Currently, Carter Wegman MACs are popular. Before that, HMAC was popular. What was popular before HMAC? Was it CBC-MAC? Something else? I know about NIST FIPS 113 "Data Authentication Algorithm" ...
Z.T.'s user avatar
  • 824
7 votes
9 answers
1k views

Soft question: What are examples of beautiful proofs in cryptography? [closed]

These may include any proofs, reductions, constructions, etc. For example, simple solutions to problems which at first sight seem difficult. Elegant construction that hide deep mathematical concepts, ...
Snoop Catt's user avatar
  • 1,297
61 votes
6 answers
9k views

Soft question: Examples where lack of mathematical rigour cause security breaches?

Cryptographic tools can often become adopted even when their security proofs lack mathematical rigour - or altogether missing. Are there famous cases of security breaches in the industry, where the ...
Snoop Catt's user avatar
  • 1,297
6 votes
0 answers
131 views

What is the "brand X" cipher mentioned in the Usenet thread about RC4?

In the original Usenet thread about RC4 when it was finally reverse engineered, a user by the name of Michael Johnson mentioned that the RC4 algorithm looked surprisingly like another proprietary ...
forest's user avatar
  • 15.2k
7 votes
0 answers
237 views

Why did Rabin use $x(x + b)$ instead of just $x^2$ in the original paper?

Encryption in the original Rabin scheme took a message $x$ and computed $x(x + b) \bmod n$, where $0 \le b \lt n$ and $n$ is the product of two secret primes $p$ and $q$. The private key is defined as ...
forest's user avatar
  • 15.2k
10 votes
0 answers
658 views

What is the origin of the phrase "Don't roll your own crypto"?

The phrase is well-known and widely used, it is often attributed to Bruce Schneier and is indeed relevant to his Schneier's Law. However, I wasn't able to find this specific wording among Schneier's ...
rkiyanchuk's user avatar