Hi,

What

I am trying to modify the encrypt, decrypt and keygen modules to support SECP256K1 and AES-GCM 256, but the decryption fails.

Why

Since most of the publicly available implementations of ECIES support this curve, I wanted to give it a try.
I was able to modify the example to generate keys.

• Public key is of 65 bytes in length and private key is 32 bytes in length.
• Encryption succeeds, and all the verification of public-private pairs succeed.
• Decryption is OK until the GCM tag verification. But fails to authenticate the tag.

I did some debugging and found out that the AES key derived from HKDF is different for encrypt and decrypt.
But for the Curve448 example01, the keys are the same in encrypt and decrypt.

I was not able to figure out why I was getting a different result. Can anyone from @GlitchedPolygons help me out?

Hi, I was trying to use your code and when using encrypt.c I got the error that ccrush.h could not be found. However when I search the internet I can not find the ccrush library anywhere. Thank you in advance for your help.

I am pretty new to coding so my issue might be due to some beginner mistake.

Even though signing and verifying is outside of the scope of ECIES, it'd still be neat to have matching Ed25519 and Ed448 example implementations inside the programs/ collection. A simple CLI with just two parameters as seen in the others is already enough... Keep it simple too!