What are the fundamental roots of modern symmetric encryption?

Question

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 problem is fundamental to modern key exchange algorithms.

Can modern day symmetric encryption methods be similarly traced back to particular fundamental roots or building-blocks? If so, what are they?

Is there a common grandparent (or few) that most modern symmetric crypto such as AES or ChaCha can be undeniability related to?

AES for example isn't a Feistel cipher, it's a substitution permutation network — ambiso, Commented Dec 9, 2020 at 17:23
One of the most essential concepts for symmetric crypto may be Shannon's confusion and diffusion principle. — ambiso, Commented Dec 9, 2020 at 17:25
@cisnjxqu Regarding AES I know. I'm (tentatively) asking whether the SP-network/etc is a little brother of Feistel. Or Feistel with extra pieces. Or whether there is anything that is. — Modal Nest, Commented Dec 9, 2020 at 17:39
To add to @cisnjxqu's suggestion, Shannon also formulated the concept of a product cipher. And of course, of perfect security. All of these are in the same paper. — Luis Casillas, Commented Dec 9, 2020 at 21:54

SSA · Accepted Answer · 2020-12-09 13:39:42Z

-2

There are a few here.

Block ciphers like DES and its modes are based of Feistel Cipher, AES is based on Rijndael.
Others like FOX64 based on Lai-Massey scheme.
Other are are stream ciphers like RC4.

So, These are some of the schemes which are used in todays symmetric key ciphers.

answered Dec 9, 2020 at 13:39

SSA

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$\begingroup$ I think you've misunderstood my question, or maybe it isn't clear. I'm asking for the fundamental roots (if any) of modern symmetric ciphers. I'm aware that stream ciphers like ChaCha exist , my question is about the roots of such functions. All of what you've listed are clearly more related to Feistel than Caesar, for example. $\endgroup$
– Modal Nest
Commented Dec 9, 2020 at 13:56
3

$\begingroup$ AES is not based on Rijndael, AES is Rijndael. Rijndael was selected as part of the AES standardization process to become AES. $\endgroup$
– ambiso
Commented Dec 9, 2020 at 17:22
2

$\begingroup$ @cisnjxqu: to be more precise, AES is Rijndael restricted to 128 bit block sizes and 128, 192 or 256 bit keys. Rijndael allows for many more options than AES. $\endgroup$
– poncho
Commented Dec 9, 2020 at 18:05

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