The present disclosure provides in various aspects an encryption device (100), a communication system and a method of exchanging encrypted data in such a network. In accordance with some illustrative embodiments of an aspect, the encryption device (100) comprises a communication interface (110), a variable key generator (120) configured to generate at least two keys, a memory (130) configured to store keys that are either generated by the variable key generator (120) and/or received at the communication interface (110), and an encryption/decryption component (140) configured to successively use keys stored in the memory (130) for encrypting a plaintext received at the communication interface (110) and for decrypting a ciphertext received at the communication interface (110), wherein the communication interface (110) is configured to communicate with an associated separate communication device which is used by a user of the encryption device (100) for communicating in a communication network.