[philsnow]

What is "Google Messages"? I can't count the number of articles people have written over time about how many first-party messaging apps Google themselves have put out (and then put down), not to mention what messaging apps get shoveled on by third-party android integrators.

> the main reason a message wouldn't be properly end-to-end encrypted in Google's Messages app is when communicating with an iPhone user, because Apple has dragged their feet on implementing RCS features in iMessage

(or with any other android user who isn't using a first-party device / isn't using this one app)

> [...] Android's equivalent cloud backup service has been properly end-to-end encrypted by default for many years. Meaning that you don't need to convince the whole world to turn on an optional feature before your backups can be fully protected.

You make it out to seem that it's impossible for Google to read your cloud backups, but the article you link to [0] earlier in your post says that "this passcode-protected key material is encrypted to a Titan security chip on our datacenter floor" (emphasis added). So they have your encrypted cloud backup, and the only way to get the key material to decrypt it is to get it from an HSM in their datacenter, every part of which and the access to which they control... sounds like it's not really any better than Apple, from what I'm reading here. Granted, that article is from 2018 and I certainly have not been keeping up on android things.

[0] https://security.googleblog.com/2018/10/google-and-android-h...

[modeless]

HSMs are designed to protect encryption keys from everyone including the manufacturer. Signal trusts them for their encryption features. It's the best security possible for E2EE backups with passcode recovery, and Apple does it too for the subset of data that they do real E2EE backups on, like Keychain passwords. Characterizing using an HSM to implement E2EE securely as "not any better than" just giving up on E2EE for messages backups is ridiculous.

[philsnow]

The HSMs that Signal and Apple are using are on-device though. Yes you still have to trust Signal / Apple to not exfil your key matter once decrypted by the HSM, but I submit that that is materially better than having the HSMs be hosted in a datacenter.