In a serverless distributed file system, the writer of a file can provide
file authentication information to a verifying machine without having to
compute a new digital signature every time a written file is closed.
Periodically, the writer compiles a list of the hash values of all files
that have been written over a recent interval, computes a hash of the
list, and signs the hash. This signed list of hash values is known as a
manifest, akin to a shipping manifest that enumerates the items in a
shipment. The advantage of using a signed manifest is that the writer
need only perform a single signature computation in order to authenticate
the writes to multiple files, rather than having to compute a separate
signature for each file, as it would if a signature were embedded in each
file.