It looks like this checksum was generated with md5sum, an implementation of the one-way hash function MD5. Md5sum can be used to verify such checksums (just compute the hash yourself and check that they are equal). MD5 produces a 128-bit hash which is supposed to be easy to compute but very difficult to fake. It should be described in any intro textbook on cryptography. (I think the CMU bookstore stocks "Applied Cryptography" by Bruce Schneier.) MD5 is being used here as an authentication mechanism rather than to catch transmission errors. (FTP uses TCP/IP which provides reliable transmission.) -dave On Mon, 23 Apr 2001 11:40:45 EDT, Zachary Uram <zu22 at andrew.cmu.edu> wrote: > how was that checksum generated and what did u do to verify it? > checksum lets u know that file didnt lose any bits when being > ftp'ed etc yes?