The fscrypt document says:
Because of the requirements to retain support for efficient directory lookups and filenames of up to 255 bytes, the same IV is used for every filename in a directory.
Questions:
What is this Initialization Vector ('IV') that is being reused? Where is it stored in the directory?
This sentence explaining the reason of IV reuse is vague. Aren't there other solutions, for example, using a synthetic IV computed from filenames?
