X’s New Encrypted Chat: Experts Warn It’s Not Trustworthy Yet

X, formerly known as Twitter, has started rolling out its new encrypted messaging feature, called XChat. The company says it offers end-to-end encryption, meaning only the sender and recipient should be able to read the messages, with X having no access. But some experts believe there are serious security flaws in how it’s implemented, raising doubts about whether it’s really safe to use just yet.

Security Concerns with XChat’s Encryption Setup

When you first set up XChat, users are asked to create a four-digit PIN, which encrypts a private key that is then stored on X’s servers. This private key is important because it’s used to decrypt messages. However, unlike Signal, a service widely praised for its security, X stores the private key on its servers, which experts argue could pose a big risk.

Signal, in comparison, keeps the private key on the user’s device. This makes it much harder for anyone, including the company behind the service, to access your messages. Security researcher Matthew Garrett raised concerns that if X doesn’t use proper security measures, such as hardware security modules (HSMs), its servers could potentially tamper with the keys or even brute-force the PIN to access private messages. X claims to use HSMs, but they’ve yet to prove it.

Could X Itself Compromise Your Messages?

Another red flag is that X admits there is a risk that a malicious insider or even X itself could compromise encrypted conversations. This could lead to a security issue known as an adversary-in-the-middle (AITM) attack, where X might secretly replace the encryption keys, allowing it to spy on messages without the users’ knowledge. This would defeat the purpose of having end-to-end encryption in the first place.

This vulnerability is particularly concerning since X gives you the public key when you communicate with them. So, even if X has implemented encryption properly, you can’t be sure that they haven’t swapped in a new key, putting your privacy at risk.

XChat Isn’t Open Source, And That’s a Problem

Unlike Signal, which is fully open-source and transparent about how its encryption works, XChat doesn’t yet offer this level of transparency. X has promised to open-source their encryption setup and publish a technical whitepaper later this year, but until that happens, it’s hard to fully trust the system. Experts like Matthew Garrett aren’t convinced, pointing out that we can't be sure about the security of XChat until it’s independently audited.

Lacking Essential Features for Better Security

Another issue with XChat is the lack of perfect forward secrecy—a crucial feature in cryptographic systems. This ensures that even if someone gains access to your private key, they can only decrypt the latest message, not all past communications. X has admitted that this feature isn’t yet available in XChat, which leaves conversations vulnerable if someone manages to compromise a user’s private key.

Don’t Trust It Just Yet

Until XChat undergoes thorough testing and a security audit by an independent party, experts are advising users to be cautious. Matthew Green, a cryptography expert from Johns Hopkins University, also recommends against trusting the service for now, suggesting that it’s no more secure than unencrypted messages on X.

In other words, XChat might look good on paper, but until all the security gaps are addressed, it’s safer to stick with tried-and-tested platforms like Signal for private communication.

Conclusion: Caution Is Key

While X is making moves into the world of secure messaging with XChat, it’s not quite there yet. The system’s current flaws—such as storing private keys on its servers, the possibility of manipulating encryption keys, and missing features like perfect forward secrecy—mean that it’s not ready to be fully trusted with sensitive communications.

Until X can prove that their encryption system is up to par and undergoes a full audit, users should be cautious. The promise of end-to-end encryption is great, but for now, XChat may not be the reliable choice many expect it to be.