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The Joy of Cryptography

joyofcryptography.com

51–60 of 105 posts

Re: The Joy of Cryptography

#51

For those looking for a more exercise-oriented approach to cryptography, the Cryptopals challenge ( https://cryptopals.com/ ) is an excellent way to discover cryptography step by step with 64 exercises with an increasing difficulty level

Thank you! Looks like crypto version of Project Euler and Rosalind.

Re: The Joy of Cryptography

#52
Myself going from "web designer" to a "zero-knowledge proof cryptographer" (I'm a coauthor of Dalek Bulletproofs implementation, the cleanest API, documentation and fastest ZKP system ever) I'm sad to see crypto textbooks spending most of the time on symmetric ciphers, going through the same nonsense like ECB and then touching asymmetric only with RSA and annoying GCD stuff when everyone moved onto elliptic curves already.

I'd like to see material around modern stuff (Keccak and ECC) with only a cursory discussion of pitfalls of the past standards in contrast with the current stuff. And more time on asymmetric, discrete log and fiat-shamir protocols that are so much fun and require really a 7th grade algebra to grasp.

I've also made a couple of videos on ECC basics with that approach: https://www.youtube.com/channel/UCk0r9S76wngNPJb_GlhJYdw

EDIT: what i mean, is focus first on how to use primitives and what they promise, rather than how they actually work. Once you feel like you can play with these legos, it's more fun to dig deeper and see why ECDLP is hard and how ciphers are made. But please don't start from within - it's an annoying boring mess that distracts from the true beauty: the cool things you can build with these tools.

Re: The Joy of Cryptography

#54

Myself going from "web designer" to a "zero-knowledge proof cryptographer" (I'm a coauthor of Dalek Bulletproofs implementation, the cleanest API, documentation and fastest ZKP system ever) I'm sad to see crypto textbooks spending most of the time on symmetric ciphers, going through the same nonsense like ECB and then touching asymmetric only with RSA and annoying GCD stuff when everyone moved onto elliptic curves al…

> what i mean, is focus first on how to use primitives and what they promise

These sorts of "provable security" textbooks (like the one in the article) try and do that. They emphasise less the exact inner workings of algorithms, and more on what they supposedly achieve. Various kinds of security proofs are possible. This school of thought in cryptography does also allow you to argue fairly convincingly that some concrete ciphers are secure. So it can talk about both the inner workings of ciphers as well as what security properties they achieve.

The "provable security" approach seems to be in line with your suggestion. In fact, it was the framework under which Zero Knowledge Proofs were developed. Not every cryptographer knows about that though, so I'm not sure if you were aware...

Re: The Joy of Cryptography

#56
post #13

Earlier quoted context omitted.

Somehow discrete math was the only math I understood in CS. Calculus, on the other hand, completely eluded me.

If the whole of math were represented by the surface of the planet, "discrete math" would be more than half of it. Calculus (i.e. differentiation/integration on the reals) on the other hand, would be a city. Perhaps a very populated city, but just one. It's a shame that match curriculum for non-math-majors is an all-roads-lead-to-calculus affair. I think we scare a lot of potentially talented people away from math wi…

Well this isn't true at all. I'm shocked anyone would upvote this nonsense.

Re: The Joy of Cryptography

#57
post #40

Earlier quoted context omitted.

RSA is still in wide use in both old and new deployments (e.g. it is still the majority of TLS handshakes). Elliptic curves are faster and use smaller keys, but they're also a more fragmented ecosystem; plus, in particular for the older NIST curves, there is the unshakable fear that they're backdoored by the NSA (since they use magic unexplainable numbers, which RSA does not). Thankfully ed25519 gave us an alternativ…

No cryptography engineer seriously believes the NIST P-curves are backdoored, and they are in widespread use. Ed25519 is a signing scheme; it isn't a replacement for the RSA in classic TLS --- you'd be thinking of Curve25519, its sibling. The benefit of the 25519s isn't "no magic numbers", it's a structure that makes it easy to implement relatively safely. And all these curves work over prime subfields. This is all 1…

I wouldn't contest that no crypto engineer "seriously believes NIST P-curves are backdoored", but I know some high profile crypto engineers who seriously think and demonstrate how they might be flawed and could have been backdoored since day one. [1] [2]

It's almost impossible to prove they were backdoored, but considering the sensitivity of the subject, I understand why many consider this unknown a reason to distrust NIST P-curves.

[1] https://cr.yp.to/talks/2013.05.31/slides-dan%2Btanja-2013053...

[2] https://cr.yp.to/newelliptic/nistecc-20160106.pdf

Re: The Joy of Cryptography

#58
post #13
post #5

> All the sensible textbook titles were already taken. Actual joy not guaranteed. Like a lot of people (I imagine) I made it through a CS bachelors program not really ‘getting’ the discrete math combinatorics part. Crypto is an area where those concepts really really matter. It’s great to see this resource available!

Somehow discrete math was the only math I understood in CS. Calculus, on the other hand, completely eluded me.

For what it’s worth, I had the damndest time with Calculus until I got a good professor. When he explained it, everything clicked. A good teacher makes a massive difference. It might be worth giving it another go.

Re: The Joy of Cryptography

#59
Again I complain on the irritating habit of non-descriptive naming of files.

book.pdf

Really? I'm saving the file for a later review and this name will guarantee I either completely lose the file or will spend more time than necessary to locate it. The other option is to rename the file on saving, which is some work which needs to be performed by each user, instead of being done just once on the source. I think this is just impolite.

Here's a proper name you can copy-paste:

Mike_Rosulek_-_The_Joy_Of_Cryptography_(draft_2021-01-03).pdf

PS: The short-link-for-verbal-sharing problem is solved via a symbolic link.

Re: The Joy of Cryptography

#60
post #45

Is it available in a format other than PDF? Like HTML or MOBI for example? PDF is very inconvenient to read on small screens like phones or kindle. Thanks!

In case you haven't tried, I suggest using koreader. It has a good combination of a reliable crop and a usable reflow feature. Not ideal, but it's much better than constant zooming and moving the view around.

https://koreader.rocks/

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