TL;DR

Learn by doing: cryptopals.

The word crypto has evolved in the latest years to mean scams. This is a shame.

The origin, you know, is in cryptography. Bruce Schneier refers to it as something aimed at protecting files (here):

There are two kinds of cryptography in this world: cryptography that will stop your kid sister from reading your files, and cryptography that will stop major governments from reading your files.

Anyway, the evolution I saw in time is that blockchain technologies are deeply rooted in cryptographic stuff, which gave spur to cryptocurrencies, which gave spur to the wider cryptothing that’s mostly a scam. Hence, much like the word hacker, it gained a negative connotation in a wider audience.

Suggested view (2+ hours!): Line Goes Up.

Again, this is a shame because cryptographic stuff is interesting and fascinating, and there’s a lot to learn without having anything to do with convincing people to pay you tons of money for a place in a list.

So I’ve been very pleased to find out about cryptopals. It’s no secret I love challenges (I mean, programming challenges), because they’re fun and there’s often (always?) something to learn.

Cryptopals is no exception:

This is a different way to learn about crypto than taking a class or reading a book. We give you problems to solve. They’re derived from weaknesses in real-world systems and modern cryptographic constructions. We give you enough info to learn about the underlying crypto concepts yourself. When you’re finished, you’ll not only have learned a good deal about how cryptosystems are built, but you’ll also understand how they’re attacked.

So, if you’re interested into learning something, I recommend it. I’m currently at the beginning of the third set, and I’m having a lot of fun and understanding.

Stay… safe!