A system for providing secure communication of a message between parties is provided. The system includes first and second communication devices. The first communication device includes a first list of numbers and a first number selector for periodically selecting a different number in the first list. The first communication device further includes a first encryption key generator for generating a first encryption key at a certain time. The first encryption key generator uses the number selected by the first number selector at a certain time to generate the first encryption key from the first list of numbers. The first communication device also includes an encryptor, for encrypting a message using the first encryption key, and a transmitter for transmitting the encrypted message. The second communication device includes a receiver for receiving the encrypted message and a second list of numbers, the second list of numbers being identical to the first list of numbers. A second number selector is provided for periodically selecting a different number in the second list. The second number selector is synchronised with the first number selector such that, at any given time, the second number selector selects the same number as the first number selector. The second communication device also includes a second encryption key generator for generating a second encryption key, wherein the second encryption generator uses the number selected by the second number selector at the certain time to generate the second encryption key from the second list of numbers; the second encryption key being identical to the first encryption key. The second communication device further includes a decryptor for decrypting the encrypted message using the second encryption key. An associated method for providing secure communication of a message between parties is also provided.