Minor Description
Currently we use SHA-1 as the hash algorithm for the blob store (same as with Jackrabbit 2.x). I think it makes sense if we use SHA-256 instead:
Advantages:
- SHA-1 is considered "broken" by some experts:
http://www.schneier.com/blog/archives/2005/02/sha1_broken.html
- SHA-256 belongs to the SHA-2 family, which is recommended by NIST
for new applications:
http://csrc.nist.gov/groups/ST/toolkit/secure_hashing.html
Disadvantages:
- Longer file name
- Longer content hash
- Not compatible with Jackrabbit 2.x
For the FileBlobStore, the current implementation uses only one directory level while Jackrabbit 2.x uses 3 levels. I think we should use two levels for Oak, to avoid too many files in the same directory.