[Cryptography] New White Paper: GhostLine - Information-Theoretically Secure Multi-Party Chat

[Ferecides de Siros]

On Monday, September 8th, 2025 at 16:14, Jon Callas <jon at callas.org> wrote:

> If you're going to use Mechanism X to transmit your pads, why not use that same mechanism to just transmit the message?
> 
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Hi Jon,

Thank you for this brilliant historical perspective - it's truly a masterclass in the practical 
realities of information-theoretic security. Your analogy of Sauron's seduction perfectly 
captures both the allure and the operational challenges of one-time pads.

You've articulated the fundamental paradox elegantly: if we have a secure channel for pad 
distribution, why not use it directly for messages? GhostLine indeed targets the specific 
niche where pad distribution is solvable via secure out-of-band channels, and where 
participants value mathematical guarantees over operational convenience.

Your point about the transmission paradox has actually inspired a potential future direction 
for GhostLine: using an initial large in-person OTP distribution to bootstrap a ratcheting 
mechanism where each session generates a new OTP for the next session. 
This would maintain information-theoretic guarantees while reducing the operational burden 
to a single initial distribution - essentially key ratcheting with information-theoretic 
security rather than computational.

This is currently just a conceptual idea rather than an implemented feature, but it directly 
addresses the operational challenges you highlighted. I would genuinely value your thoughts 
on this approach, given your deep experience with practical cryptography.

The current system explicitly acknowledges in section 3.1 that security ultimately reduces 
to the initial distribution mechanism, but once established, provides guarantees no 
computational cipher can match. Your credit card encryption story illustrates exactly why 
this matters when data size permits.

Thanks for adding such valuable historical context and for stimulating new thinking on this 
challenging problem.

Best,
Hitokiri
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