Matthew Green / A Few Thoughts on Cryptographic Engineering:

An analysis of X's new XChat features shows that X can probably decrypt users' messages, as it holds users' private keys on its servers  —  Update 6/10: Based on a short conversation with an engineering lead at X, some of the devices used at X are claimed to be using HSMs.  See below.

Matthew Green / A Few Thoughts on Cryptographic Engineering:

An analysis of X's new XChat features shows that X can probably decrypt users' messages, as it holds users' private keys on its servers  —  Update 6/10: Based on a short conversation with an engineering lead at X, some of the devices used at X are claimed to be using HSMs.  See below.

Source: TechMeme
Source Link: http://www.techmeme.com/250609/p47#a250609p47