HashKeeper

HashKeeperis adatabaseapplication of value primarily to those conductingforensicexaminations ofcomputerson a somewhat regular basis.

Overview

HashKeeper uses theMD5filesignaturealgorithmto establish unique numeric identifiers (hash values) for files "known to be good" and "known to be bad."

The HashKeeper application was developed to reduce the amount of time required to examine files on digital media. Once an examiner defines a file as known to be good, the examiner need not repeat that analysis.

HashKeeper compares hash values of known to be good files against the hash values of files on a computer system. Where those values match "known to be good" files, the examiner can say, with substantial certainty, that the corresponding files on the computer system have been previously identified as known to be good and therefore do not need to be examined.

Where those values match known to be bad files, the examiner can say with substantial certainty that the corresponding files on the system being examined that the files are bad and therefore require further scrutiny. A hash match on known to be bad files does not relieve the examiner of the responsibility of verifying that the file or files are, in fact, of a criminal nature.

History

Created by theNational Drug Intelligence Center(NDIC)—a component of theUnited States Department of Justice—in 1996, it was the first large scale source for hash values of "known to be good" and "known to be bad" files. HashKeeper was, and still is, the only community effort based upon the belief that members of state, national, and international law enforcement agencies can be trusted to submit properly categorized hash values. One of the first community sources of "known to be good" hash values was the United StatesInternal Revenue Service.The first source of "known to be bad" hash values was theLuxembourgPolice who contributed hash values of recognized child pornography.

Availability

HashKeeper is available, free-of-charge, tolaw enforcement,militaryand othergovernment agenciesthroughout the world. It is available to the public by sending aFreedom of Information Actrequest to NDIC.

In the 2012 United States budget, NDIC was de-funded and closed its doors on June 16, 2012. The availability and future of HashKeeper is uncertain.

Sources

HashKeeper Overview,National Drug Intelligence Center.

See also

• National Software Reference Library
• Rainbow table

References

http://www.justice.gov/archive/ndic/ndic-moved.html

http://www.nsrl.nist.gov/nsrl-faqs.html#faq12