Lol, so like ... all encryption schemes since the 70s?
Hashing is not encrypting.
You can learn more about the topic here, https://www.okta.com/identity-101/hashing-vs-encryption/
Load this page, https://en.wikipedia.org/wiki/Advanced_Encryption_Standard
Ctrl-F "hash". No mention of it.
Before being pedantic at least check out the url in that comment to get the basics going.
You're correct that a pure encryption algorithm doesn't use hashing. But real-world encryption systems will include an HMAC to detect whether messages were altered in transit. HMACs do use hash functions.
> Hashing is not encrypting.
> You can learn more about the topic here, https://www.okta.com/identity-101/hashing-vs-encryption/
Thank you for that link. Your original comment implied that Signal's threat model should have included an attacker-controlled end. The only way to do that is to make decryption impossible by anyone, including the intended recipient. A labyrinthine way to do that would be to substitute the symmetric-encryption algorithm with a hash algorithm, which of course destroys the plaintext, but does accomplish the goal of obfuscating it in transit, at rest, and forever.