The webcrypto api also can't stop the server from sending malicious javascript to a user which when run uses the webcrypto key to decrypt the user's data and send it back to the server. Also, if the server is malicious on the first connection, then the server could just not use the webcrypto api to begin with, and just make use a key that the server knows instead.
The webcrypto api is still pretty cool though. I've been hoping for an excuse to use it sometime.
The webcrypto api is still pretty cool though. I've been hoping for an excuse to use it sometime.