Signal protocol prevents replay attacks as every message is encrypted with new key. Either it's next hash ratchet key, or next future secret key with new entropy mixed via next DH shared key.
Private keys, probably not. WhatsApp is E2EE meaning your device generates the private key with OS's CSPRNG. (Like I also said above), exfiltration of signing keys might allow MITM but that's still possible to detect e.g. if you RE the client and spot the code that does it.
Whatsapp didn't implement Signal's protocol verbatim. They appropriated the core cryptographic security and then re-implemented the rest on their own servers. This removes all guarantees of secrecy as long as they can run arbitrary code on the servers they own.
Wouldn't ratchet keys prevent MITM too? In other words if MITM has your keys and decrypts your message, then your keys are out of sync from now on. Or do I misunderstand that?
maqp|29 days ago
Private keys, probably not. WhatsApp is E2EE meaning your device generates the private key with OS's CSPRNG. (Like I also said above), exfiltration of signing keys might allow MITM but that's still possible to detect e.g. if you RE the client and spot the code that does it.
uoaei|26 days ago
TurdF3rguson|29 days ago