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FC1 Algorithm Ushers In The Era Of Post-Alien Cryptography

Document Type Expired Internet-Draft (individual)
Expired & archived
Author Michele Fabbrini
Last updated 2023-11-21 (Latest revision 2023-05-20)
RFC stream (None)
Intended RFC status (None)
Stream Stream state (No stream defined)
Consensus boilerplate Unknown
RFC Editor Note (None)
IESG IESG state Expired
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft is available in these formats:


This memo aims to introduce the concept of "post-alien cryptography", presenting a symmetric encryption algorithm which, in our opinion, can be considered the first ever designed to face the challenges posed by contact with an alien civilization. FC1 cipher offers an unprecedented grade of confidentiality. Based on the uniqueness of the modular multiplicative inverse of a positive integer a modulo n and on its computability in a polynomial time, this non-deterministic cipher can easily and quickly handle keys of millions or billions of bits that an attacker does not even know the length of. The algorithm's primary key is the modulo, while the ciphertext is given by the concatenation of the modular inverse of blocks of plaintext whose length is randomly chosen within a predetermined range. In addition to the full specification here defined, in a related work we present an implementation of it in Julia Programming Language, accompanied by real examples of encryption and decryption.


Michele Fabbrini

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)