Originally Posted by Donald E. Pauly
Steele's attorney's have made a big stink over the fact that the original recordings were destroyed. They are stuck in the 20th century. All copies of digital recordings are properly considered original. Opinion only, that is not neccessarily true.
A hash function is somewhat like a check sum. All the bits of the recording are entered into a complex mathematical function. In this case that function is used to produce a 32 byte string of digits called a hash. This same function can be used on a copy of that recording to see if it is still exactly the same as the original.
The 16-byte MD5 hash function has been 'spoofable' for years. How do you know a 32-byte hash can't be spoofed?
Here is an explanation of the details of the recorder by an FBI examiner. The original link is a photo type pdf file and I retyped it.
The FBI evidence labs have a history involving evidence tampering
Of course the FBI's evidence handling procedures are self-serving, but to avoid criticism they should provide more details on how they preserve the authenticiy of the alledged evidence- not just "trust us".
See: Info on how 16-byte hashes are spoofed.