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From: "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com>
Newsgroups: sci.crypt
Subject: Re: fun with nonces
Date: Sun, 7 Jul 2024 13:03:44 -0700
Organization: A noiseless patient Spider
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On 7/5/2024 1:46 PM, Stefan Claas wrote:
> Chris M. Thomasson wrote:
>> On 7/4/2024 10:47 AM, Stefan Claas wrote:
>>> Let's assume Bob travels a lot and he wishes to
>>> communicate encrypted with Alice, while using an
>>> encryption program which uses a nonce as additional
>>> input parameter.
>>>
>>> He does not need to send Alice the nonces, once he
>>> arrived, because they both have a shared secret.
>>> Alice and Bob can generate them by themselves, no
>>> matter what timezone they are in and the nonces will
>>> be random and can be re-generated with the same values
>>> again, per day.
>>>
>>> https://github.com/stefanclaas/nfs
>>>
>>> I Have to do a README which explains this scenario
>>> a bit. Hope you like the idea!
>>>
>>
>> Hopefully the nonces were created by a TRNG such that they cannot be
>> repeated expect by pure chance... Fair enough?
>>
>> Every PRNG has a period and a way to set the starting point.
> 
> Well, they can be also pseudo-random. Mine are deterministic,
> based on a passphrase and date while using hkdf.
> 

Can somebody try to get at things where they can gain educated guesses 
at your schedule, so to speak?