Marc Espie <es...@nerim.net> wrote: > > And now we are back to my starting poit. The checksum is not used > > in rsync as a pure checksum to find accidental errors. That was my > > critic. > > No, it is. Really. Read the papers. Do your homework, check the maths.
I have read this: http://rsync.samba.org/tech_report/ It confirms that it supposes: A=B if hash(A)=hash(B). The last is checked in the server for constructing the file in the client. > > >From a checksum I expect two things: (1) the pre-images of elements > > in the range have all similar sizes, > Why ? This makes no sense, and is in contradiction with (2). No contradiction. Similar sizes mean similar cardinality. The pre-image of an element is a subset of the domain. An extreme case would be that most of the strings in the domain are mapped to a single element. This would be similar to having a hash with a very small range. > All you're doing is trying to spread FUD about perfectly fine programs. I do not have doubt that the probability of getting a false file is very small, perhaps indeed neglectable, specialy after the lot of checks. I think also with very bad hashes one could also get good results in practice with the same algorithm. How you presume to know my intentions? Again making persons the object of discussion? Jan Stary <h...@stare.cz> wrote in a personal mail: >> We must hope, believe and pray. > > You, in particular, need to shut up and read. Normaly I am glad to receive personal mails, but my Email is public here not for this kind of misuse. Rodrigo.
