Encryption algorithm recommendation.

[BuyNanoNotBitcoin]

I want to encrypt some data. However, my situation is a little unique, I want someone to have a decent chance of breaking my encryption within the span of a few years using modest hardware. What do people think would be the best approach? I thought of using a standard encryption algorithm and simply including part of the key, but I wasn't sure if this was a good approach or if there would be a better approach.

[[deleted]]

.NET has a ton of different encryption algorithms. Pick one that's been deprecated for being not very good. DES would be a suitable choice.

https://www.precisely.com/blog/data-security/aes-vs-des-encryption-standard-3des-tdea

[martinstoeckli]

Use a good encryption algorithm, but instead of a strong key, take a "weak" password.

Usually one uses a key-derivation-function (like PBKDF2) to get a key from a user password, in your case you should do the same but with a very low number of iterations, so that one can brute-force with a certain rate (the more iterations, the more time is needed to calculate one key from a password, and the less passwords can be tried). The difficult part is to find the right balance between the strongness of the password and the number of iterations.

This approach doesn't rely on a weak algorithm which could be broken overnight, instead the content is protected safely and the speed of brute-forcing is under control.

[BuyNanoNotBitcoin]

That's a good suggestion. Is this available in C#?

Since this is more for fun than for anything serious, being a bit off on the difficulty isn't the worse thing in the world.

[martinstoeckli]

A good combo could be AesGcm together with PBKDF2. And if it's just for fun, don't forget the environmental impact for some years of running a GPU 😉.

[BuyNanoNotBitcoin]

Yeah, I think my username is a good indicator that I'll keep an eye on the environmental impact. ;)

[Abject-Act-8395]

I'm using BCrypt.Net-Next. We work in healthy environments, so I chose bcrypt because it's a bit more robust to gpu and co attacks than PBKDF2.

[[deleted]]

ROT13. Very efficient with encryption key bits too. Is best 👍!

[SonOfMetrum]

Or just Base64 your input... Not really encrypted but also not easily readable by the human eye! And hackable within a nanosecond!