twinkle-notes

Thank you for digging into the code. This is why we are going open source. The encryption you are referring to is for encrypting a list of keys for your local notes storage, which is not exactly part of the end-to-end encrypted syncing. Since you have got this far, could you please have a look at: https://github.com/twinkle-labs/twinkle-notes/blob/8ad7d9d0b... > They must be unpredictable I am wondering if that is necessary, because the hacker can't perform those attacks without the user's actively using the app at the same time. From what I learned, the attacking process requires the presence of key somewhere. If the attacker can get on user's device while one is using it, then it's almost a hopeless situation. Please educate me if I am wrong.

> end-to-end encrypted https://github.com/twinkle-labs/twinkle-notes/blob/45206f9d6... For AES in CBC mode, IVs have two requirements: 1. They must never repeat. 2. They must be unpredictable. Generating them from a SHA256 hash of some low-entropy data is not a good practice. https://paragonie.com/blog/2016/05/how-generate-secure-rando... Furthermore, not authenticating your ciphertext means padding oracle attacks can be launched against the app. https://robertheaton.com/2013/07/29/padding-oracle-attack/