Authenticating digital documents

Judah Levine, a physicist at the National Institute of Standards and Technology has received a patent for a system that applies a signed time stamp to any digital file.

Traditionally, when you need a document authenticated, you take it to a notary public, a person licensed to affix an official seal, date and signature to it. But what about electronic documents or files? Thanks to National Institute of Standards and Technology (NIST) physicist Judah Levine, there may soon be a solution.

Levine, a researcher in NIST’s Time and Frequency Division, recently received a patent (no. US 6,393,566 B1) for a system that applies a signed time stamp to any digital file, proving that it existed at a certain date and time in a specific form.

The time stamp in the signature is traceable to the NIST time standard. Any user can verify the authenticity of the file and its time stamp. The authentication procedure does not require NIST participation, and NIST does not need to maintain a copy of the original file.

If the file or original NIST time stamp have been altered in any way since the NIST signature was applied, the authentication process will fail.

Among the many situations where the NIST electronic time stamp might be used are the processing of time-critical commercial transactions such as bills of sale or legal matters such as contracts and wills.

It also may be used to establish authorship and date of creation for digital audio and digital video recordings, and to support services similar to registered mail with return-receipt requested.

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