Elm: SignSign (sign2x) Multi-sign documents locally relying on math for security

Sign Sign (sign2x). Multi-sign documents locally (privacy) relying on mathematics for security and correctness

Have you ever tried to sign a document for your bank based on the proprietary solution provided by NemID + e-Boks? Or have you tried one of the many other closed and proprietary solution (and wannabe monopolistic): Visma Addo, Penneo, DocuSign, ...?

If yes, you will find out that most of these solutions are based on you uploading your documents to their servers, both for signing as well for validating. Already based on the approach that you will have to submit confidential documents to some third party should turn on the red light but, what if any of these companies goes into bankruptcy, what will happen to your valid "signed documents"?

What if I told you that you soon will be able to download a GPL-3.0 SPA (Single Page Application) from a website (https://sign2x.org, please mirror when online) and locally sign your documents or validate without anybody else having to know about it?

To achieve this, the SPA relies on well known cryptographic approach which is recognized and accepted worldwide (RSA which is used to handle, among others, safe bank transaction) and the core library on which it's built-on that is used by the most widely-used cryptographic e-mail provider in the world (OpenPGP.js).

An extra feature of the upcoming SPA is that it provides a feature that allows to multi-sign documents with an extra bit of mathematics (𝑞 : ℕ<0XA061 → ℤ*<0XA061, 𝑞(𝑥) = 0X9D97 + 0X16A0𝑥 + 0X300A𝑥2) to ensure that some,any,all of the signers comply with the requirements of the document.

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The talk was given at Open Source Days as a last minute substitution talk. In this talk, we will certainly dig into code as well (40 minutes vs 3 hours)

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We have set up a collaboration with Prosa, who generously offered to provide a location for our regular meetups. Please see Prosa's Calendar for more details: Prosa Calendar (https://www.prosa.dk/kalender/hele-kalenderen/)

The ADA meeting room fits about 25 people and if we need more space, we can use the canteen (PASCAL), which has a capacity of +50.

Regards,

Ramón and Joakim