# OSdata.com

Thoughts on a secure form of communication.

One Time Pad (OTP) is the only known truely secure method of encrypting a message.

One time pad works by using a different secret key (pad) for every message.

One time pad was first mentioned by Frank Miller in 1882 and was first implemented in teletype paper tape by Captain Joseph Mauborgne (U.S> Army SIgnal Corps) and Gilbert Vernam (AT&T) in 1917. In 1945 Claude Shannon wrote a classified paper (declassified in 1949) that proved that one time pad is absolutely secure (as long as the pads are not compromised).

One time pad remains in use for the most secure communications, but because of the overhead of distributing mathcing pairs of randomly generated pads, it is otherwise rarely used.

## time based key

If two computers had a matching set of keys (pads) and each key was associated with a particular time and date, the clear channel time and date of transmission could be used by the recipient of the message to find the matching key (pad) in a giant look-up table.

## key generating function

It would be possible to replace the giant table of keys with a key generatign function that takes the time and date and generates the shared key.

Functions can be much more compact than keys.

The inherent problem with a single key generating function is that analysis of the messages should eventually reveal the underlying function, compromising the security of all of the messages.

## table of functions

A partial solution would be to have multiple functions. If one had a different function for every message, this would essentially be equivalent to a true one time pad as long as the generating functions collectively have the same relationship to each other as true random numbers have to each other (a rather high standard)..

A reasonable set of generating functions randomly distributed in the time-date based lookup would approximate a true one time pad.

It would be important to make sure that the time generating a key must be equal for every key generating function, but this can be accomplished by delaying all generating functions to match the speed of the slowest generating function.

A group of researchers from UCLA, IBM Research, and the University of Texas at Austin wrote a paper entitled “Candidate Indisyinguishability Obfuscation and Functional Encryption for all circuits” which used a method called Multlinear Jigsaw Puzzles that allowed for a functional encryption scheme. See Cryptology ePrint Archive: Report 2013/451 and click on the link for available formats.

## semi-secure

The goal is to find a sweet spot where the number of generating fucntions is small enough to reasonably store while still large enough to prevent easy decryption.

I’m not sure if that sweet spot actually exists.

## OSdata.com is used in more than 300 colleges and universities around the world

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### OSdata.com is used in more than 300 colleges and universities around the world

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