Yes, you need the recipient's public key, and they need your public key. Your private key is used to perform a key exchange using X25519 (https://www.kryptor.co

Yes, you need the recipient's public key, and they need your public key. Your private key is used to perform a key exchange using X25519 (https://www.kryptor.co.uk/technical-details#private-and-public-keys https://www.kryptor.co.uk/technical-details#private-and-publ...). Unlike age, this key exchange is authenticated, meaning you can know who sent you the file. Unfortunately, due to that and the fact that the file format is fixed rather than variable in length, Kryptor currently only supports specifying one recipient at a time. Implementing multiple recipient support is a nice idea, but it's quite tricky to do and would require creating different files for different people.