Re: [ftpext] New Version Notification for draft-bryan-ftp-hash-05

[Iljitsch van Beijnum <[e-mail]>]

A more efficient and less DoS-prone way to implement this would be for the client to tell the server the hash, and for the server to tell the client whether the file matches the hash.

To optimize this, the hash wouldn't be a straigh hash over the entire file, but consist of three parts: the file length, a hash over a small part of the file (say, the first and last kilobyte) and finally a hash over the entire file. So if the length doesn't match, the file doesn't match the hash and there is no need to access the file. If the hash over the small part doesn't match, there is no match and hashing the entire file is avoided.

Nitpick: repeating the first part of the abstract in the introduction verbatim is a bit annoying.