Comment by basch

16 hours ago

they can also just .. brute force passwords. the pin to encrypt fb messenger chat is 6 digits for example.

but that is a pin and can be rate limited / denied, not a cryptograhpic key that can be used to brute force and compare hash generations (?)

  • They likely wouldn’t rate limit themselves, rate limiting only applies when you access through their cute little enter your pin UI.

    • The PIN is used when you're too lazy to set an alphanumeric pin or offload the backup to Apple/Google. Now sure, this is most people, but such are the foibles of E2EE - getting E2EE "right" (eg supporting account recovery) requires people to memorize a complex password.

      The PIN interface is also an HSM on the backend. The HSM performs the rate limiting. So they'd need a backdoor'd HSM.

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