Proof of data authenticity

Export data from any web application and prove facts about it without compromising on privacy.

What can TLSNotary do?

With TLSNotary, you can create cryptographic proofs of authenticity for any data on the web, even your private data. Using our protocol you can securely prove:

Private information about yourself.
You received a private message from someone.
You received a money transfer.
A snapshot of a webpage.
You were blocked from using an app.
You have access to an account.

Is it secure?

One may assume that TLSNotary requires a “man-in-the-middle” setup where the Notary snoops on the connection with the webserver. Fortunately, this is not true! Data is kept private even from the Notary.

See below for more details on how it works.

What's the catch?

TLSNotary does require a trust assumption. A Verifier of a proof must trust that the Notary did not collude with the Prover to forge it. This trust can be minimized by requiring multiple proofs each signed by different Notaries.

In some applications the Verifier can act as the Notary themselves, which allows for fully trustless proofs!

How it works

TLSNotary leverages the widely-used TLS (Transport Layer Security) protocol to securely and privately prove a transcript of communications took place with a webserver.

The core of the TLSNotary protocol involves splitting TLS session keys between two parties, the Prover and the Verifier. Through secure multi-party computation (MPC), the Prover's requests to a TLS-enabled webserver are encrypted and authenticated.

During the protocol neither the Prover nor Verifier are in possession of the full TLS session keys, they only hold respective shares of those keys. This preserves the security properties of TLS while enabling the Prover to prove the authenticity of the communication to the Verifier.

All of this is achieved while maintaining full privacy. The unencrypted communications remain hidden to the Verifier, and optionally the identity of the server can remain private as well.

Moreover, our protocol operates transparently to the webserver. In fact, the webserver remains unaware that this process is taking place.

Since the validation of the TLS traffic neither reveals anything about the plaintext of the TLS session nor about the Server, it is possible to outsource the MPC-TLS verification to a general-purpose TLS verifier, which we term a Notary. This Notary can sign (aka notarize) the data, making it portable in a privacy preserving way.

We're rebuilding the protocol from the ground up.

Below are some development goals on our roadmap:

Implement the core protocol as a series of open-source Rust libraries
Build and release a Notary server implementation
Develop a web extension for the browser
Create developer tools to build on top of TLSNotary

TLSNotary is a public good & open source project supported by the Ethereum Foundation under the Privacy and Scaling Exploration Team.