TFL/Encryption

## Overview

In general, the asymmetric key encryption protocols of the 20th and 21st centuries can be trivially broken by anyone with access to a quantum computer and asymmetric key encryption is not used to keep anything meaningfully private. Reasonably Unbreakable Secure Encryption (RUSE) can't be broken quickly by quantum computers and is usually resistant to being broken within a decade, but operator error can make it easier to break. One-time pads (OTP) are preferred for communicating between only a few participants who can regularly meet in person to exchange new one-time pads, but scale poorly with multiple participants exchanging messages at different times and so other encryption schemes are often used. Many experienced operators assume that all encryption will be broken, and use code phrases and other tricks to confuse hostile actors. Much of modern cryptology practice is in decoding code phrases after having decrypted an intercepted message.

## Fast Asymmetric Key Encryption (FAKE)

Fast asymmetric key encryption relies on the fact that certain mathematical operations are asymmetric and cannot be reversed: performing encryption operation A on plaintext message B with public key C results in encrypted messaged D, but performing operation A on encrypted message D with public key C does not result in plaintext message B. Instead, private key E will decode encrypted message D into plaintext message A. A person wishing to receive private messages can publicly post their encryption key and not worry about having their incoming messages read by hostile actors as long as the person keeps their private key in secret.

Unfortunately, the mathematical operations that underlie FAKE are extremely vulnerable to quantum computing, and encryption schemes that would take 1000s of networked conventional computers to break in less than 100 million years can be broken by a microframe quantum computer in hours. Quantum computers are rare enough, and FAKE is useful enough, that FAKE encryption is still used. However, anyone who is seriously concerned about security for messages that are not time critical knows that any serious hostile actor has a quantum computer and will break the encryption within a few hours.

### Mechanics

FAKE is treated as *Basic Encryption* (Ultratech p 46), but requiring a Complexity 21 conventional computer to decode in an hour (Genius megacomputers are complexity 13) or a Complexity 11 quantum computer. A typical quantum microframe (Complexity 8) requires 10 hours to crack a message encrypted via public key.

## Random Access Very Large One Time Pad Encrytion (RAVLOTPE)

A key issue with OTPE is that the pad can only be used one time. This isn't a problem with two communicators speaking back and forth with each other, since they can easily track which parts of the pad have been used. However, if multiple communicators are sending messages among themselves with long delays between transit and receipt, it is possible for two or more communicators to reuse the pad and allow parts of it to be broken. RAVLOTPE is a not entirely successfully attempt to work around this problem.

RAVLOTPE pads are enormous - literally billions of times longer than any expected message. Each message starts with a plaintext index into the pad, which leads to a second encrypted index to the part of the pad actually encrypting the message. Each message sender randomly determines the two indices. Because the pads are so much larger than the messages, it is hoped that hostile actors listening in will always be pointed to an index within the pad that has not been decoded.

RAVLOTPE is a controversial system: many security experts consider it no more secure that RUSE. It shares OTPE's weakness of requiring that all participants in the encryption have full copies of the pad, and the entire pad is completely compromised if any hostile actor gains access to the pad. Also, RAVLOTPE pads are substantially longer than normal OTPE pads, and have to be replaced more regularly: an OTPE pad that is 90$ used up is still as a secure as a fresh pad, while a RAVLOTPE pad at the same usage state means that multiple messages have almost certainly been encoding with the parts of the same pad, making future messages vulnerable.