Does machine cryptography only consist of rotor machines?

Titanlord

6/8/23, 1:48 PM

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, TypeX, etc., till around 1960)
Computational Cryptography (e.g. DES, AES, RSA, etc.)
The Future of Cryptography (e.g. Quantum crypto)

The slots 1,3, and 4 are well documented and have a lot of different systems. But I'm struggling with slot 2: The heart of all the systems I found were rotors. Some were operated by mechanics, some by electro magnetism, but all use rotors for their cryptographic applications.

My questions: Does cryptography using machines only consist of rotor machines like Enigma, Purple, Typex, etc.? If other design principles exist, can someone give me an overview of them and maybe examples?

0 + 0

enigma

history

classical-cipher

kelalaka

6/8/23, 1:54 PM

Do you count M209 as a rotor machine? M209 was easier to break than Enigma!

Titanlord

6/8/23, 2:07 PM

I would say it is a portable mechanical rotor machine

Eugene Styer

6/8/23, 6:05 PM

Don't forget the Jefferson disk (mixture of a mechanical device and manual encryption) https://en.wikipedia.org/wiki/Jefferson_disk

Score:4

Crypto

Daniel S

6/8/23, 2:53 PM

I would argue that a great many cryptographic designs lie between the mechanical designs of 2 and the micro-electronic designs of 3. These designs are electronic in nature, but without the universal computation capabilities afforded by microchips. Most of these designs were based around Linear Feedback Shift Registers (LFSRs), which are easy to instantiate with basic electronic components.

To quote section 16.3 from Schneier's "Applied Cryptography" (1996)

In the early days of electronics, they were very easy to build. A shift register is nothing more than an array of bit memories and the feedback sequence is just a series of XOR gates.

...

Most designs are secret; a majority of military encryption systems in use today are based on LFSRs.

Whether one classifies such electronic (vice micro-electronic) designs as machines, computational designs or a category to themselves is a question of terminology.

Examples might include:

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Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: Does machine cryptography only consist of rotor machines?

TH: การเข้ารหัสของเครื่องประกอบด้วยเครื่องโรเตอร์เท่านั้นหรือไม่

RO: Criptografia mașinilor constă numai din mașini cu rotor?

RU: Состоит ли машинная криптография только из роторных машин?

VI: Có phải mật mã máy chỉ bao gồm các máy rôto?

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