Elon Musk said X is launching XChat with Bitcoin-style encryption

Elon Musk announced on Sunday through a post on X that the platform is rolling out an entirely new messaging tool called XChat.

According to Elon, the new feature includes end-to-end encryption, disappearing messages, support for any file type, and cross-platform audio and video calling without requiring a phone number. He said it’s built in Rust, powered by “Bitcoin-style encryption”, and developed with an entirely new system framework.

The feature works across all devices and doesn’t need a SIM card or cellular number to function, which is a huge departure from the way rivals like WhatsApp and Telegram tie accounts to phone numbers. Elon’s approach is built for anonymity, portability, and multi-platform access without depending on mobile carriers.

New system uses Bitcoin-grade encryption but faces quantum risk

Elon’s reference to “Bitcoin-style encryption” is tied to elliptic curve cryptography, or ECC. This encryption method is what Bitcoin uses to protect transactions and digital signatures. The reason it’s used is because it offers strong protection with far smaller key sizes than older methods like RSA.

A 256-bit ECC key can provide similar security to a 3072-bit RSA key, making it faster and less demanding on memory or bandwidth.

ECC works based on the math of elliptic curves over finite fields, allowing it to handle key agreements, digital signatures, and encryption through a structure that’s tough to break using traditional computing. But researchers are raising new concerns about how long ECC will actually stay safe.

It was once thought that breaking ECC with a quantum computer would take an insane amount of resources, but recent breakthroughs show that it could actually be cracked 20 times faster than originally believed. That brings up questions about how secure XChat will be in a few years when quantum machines mature.

The problem lies in what’s called the elliptic curve discrete logarithm problem, which ECC relies on. If a system could reverse that problem quickly, like a quantum computer might, it would make it easier to break into encrypted conversations or spoof digital signatures. For now, it’s still a solid cryptographic standard, but the clock is ticking on how futureproof it really is.

Cryptographic structure inside XChat built around elliptic curve protocols

XChat’s security system appears to use a mix of ECC-based schemes. One is the Elliptic Curve Diffie–Hellman (ECDH) protocol, which helps both users create a shared private key without ever sending it across the internet. Then there’s ECIES, which is what handles the actual message encryption using that shared key. Together, they make sure messages stay private from end to end.

For verifying who’s sending what, XChat could use ECDSA, the same digital signature method Bitcoin uses. There are also advanced options like EdDSA, which uses a different type of curve known as twisted Edwards curves and also allow for faster and more secure signature verification, which would come in handy for large-scale messaging apps.

The system is also capable of handling things like ECMQV, which is a more secure key agreement scheme designed to block fake users from getting in the middle of conversations.

And there’s even a possibility XChat might support ECQV implicit certificates, which allow user identities to be confirmed without needing a big centralized public key infrastructure. That kind of system could reduce reliance on big certificate authorities while still giving users verified encryption.

All these encryption tools are centered around one idea: you can multiply a number with a point on a curve, but you can’t figure out what the number was just by looking at the result. It sounds simple, but the math is complicated enough that even the best computers in the world can’t brute-force it… well at least not yet.

XChat’s codebase is written in Rust, a programming language that’s popular among developers building secure systems. Rust reduces memory-related bugs and is considered safer than older options like C++. Combined with the smaller key sizes and lower power consumption of ECC, that makes XChat optimized for both mobile and desktop use.

Whether this setup will hold against quantum attacks is still unknown. But it sure would be interesting to live through regardless.

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