[Cryptography] Cryptographic feasibility of a decentralized trust infrastructure without a master key

[Jens Weber]

Am 05.10.2026 um 04:20 schrieb Tom Mitchell:
>
>
> On Sun, Oct 4, 2026 at 17:18 zeb--- via cryptography 
> <cryptography at metzdowd.com> wrote:
>
>     > From: Jens Weber
>     > Sent: Thursday, 1 October 2026 23:35
>     > To: cryptography at metzdowd.com
>     > Subject: Re: [Cryptography] Cryptographic feasibility of a
>     decentralized trust infrastructure without a master key
>     >
>     > Ideally, AI functions would operate only within narrowly
>     authorized contexts and should not require a global view of all
>     sensitive data.
>
>     I think Data would disagree. I do too.
>
>
> Data as in Star Trek 😳
>
> Large systems, disagreement is expected.
> So build a Ven-diagram of owners, consumers, customers, users AND 
> abusers of the data and system.
> A second diagrammatic view of applicable laws including a globe of 
> governments AND note that laws  are dynamic.  So any partitioning and 
> mandatory access lists must be ephemeral. Even necessary audit data 
> will have bounds.
>
> AI functions are interesting, map mandatory access controls into AI 
> systems much as one might for an SQL data system.  The Rainbow Series 
> for trusted systems evaluation is a start.   No application will be 
> considered secure if the platform (model) is not secure.
>
> Addition of features needs to be considered. In high school math I was 
> taught the value of factorial computing. I was also taught about 
> orders of infinity. The difference between two giant (infinite) sets 
> can be small — see Aleph-null vs. Aleph-1
> The implied combinations of “stuff” gets large quickly. <=== this
>
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>
>
> Tom,
>
> thank you again for your criticism and suggestions. Your comments 
> about dynamic laws, bounded audit data, access controls and the 
> growing complexity of large systems have been very useful.
>
> I have continued modelling NOX without selecting a blockchain or a 
> specific cryptographic implementation.
>
> One problem now appears particularly difficult:
>
> Assume a hospital temporarily loses network connectivity. A physician 
> continues working with locally available credentials. During that 
> outage, the physician's credential is revoked elsewhere because the 
> key has been compromised.
>
> When the hospital reconnects, the system has to determine:
>
>   * what the hospital knew at the time,
>   * whether the credential was valid according to its last known state,
>   * when the revocation actually became effective,
>   * whether offline actions should remain valid, be flagged for
>     review, or be rejected,
>   * and how the ordering of these events can be demonstrated without
>     trusting only the local device clock.
>
> I do not want an offline mode to become a disguised master key or a 
> general bypass of authorization.
>
> This leads me to two questions for Tom and anyone else on the list who 
> would like to comment:
>
> 1.
>
>     Are short-lived credentials combined with later reconciliation a
>     reasonable architectural direction for such a system?
>
> 2.
>
>     How would you approach trustworthy event ordering and revocation
>     during network partitions without depending on one global trusted
>     clock?
>
> I am deliberately leaving the cryptographic mechanism open at this 
> stage. I am mainly interested in whether the trust model itself is 
> sensible or whether there is a fundamental flaw in the assumptions.
>
> Best regards,
> F. Ronecker
>
>
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