All files created or tools used in a forensic investigation need to include a checksum for validation against fraud. A checksum is basically the value of a file hash. If one character in the code or file is changed, the hash will produce a different checksum. This helps validate content. A specific application version will have a unique checksum different from all other versions of the software.
A good tool for Windows to use to create checksums is File Checksum Integrity Verifier (http://support.microsoft.com/kb/841290). Tool use is very simple.
Command: <File Checksum Integrity Verifier EXECUTABLE> <FILE TO CHECKSUM> A good tool pre-installed in most Linux environments to use to create checksums is md5sum.
Command: md5sum <FILE TO CHECKSUM>