Military Cryptanalytics, Part III

Re:Military Cryptanalytics, Part III by jandrese on Friday January 08, 2021 @02:11PM (#25688760)

One time pads don't necessarily have to be pen and paper. You can distribute a MicroSD card with 128GB of random bits that is used to encode/decode messages. An additional advantage of a system like this is the OTP can be encrypted so if it is captured it can't be used to decrypt old messages without further getting key material from the end user (possibly with a pipe wrench).

The biggest problem is that no matter what, the OTP ends up being some sort of physical medium that requires shipping to the end user. But really it's a scaled up version of the key distribution problem.

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Re:Military Cryptanalytics, Part III by 35fbe7d3d5b9 on Friday January 08, 2021 @02:16PM (#25688841)

> An additional advantage of a system like this is the OTP can be encrypted so if it is captured it can't be used to decrypt old messages without further getting key material from the end user (possibly with a pipe wrench).

That problem has already been solved and the websites you visit today (should!) be working the same way:

https://en.wikipedia.org/wiki/Forward_secrecy

> the key distribution problem

That is the hardest problem, especially in a system where you've got military units in unfriendly areas.

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Re:Military Cryptanalytics, Part III by mikewarot on Friday January 08, 2021 @05:27PM (#25691354)

Erasing the parts of the pad that have already been used, overwriting them with new hardware generated random numbers would seem to help out forward secrecy. Or am I missing something?

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