Duplicate works

Obtaining a copy of a registered work to use as evidence.

If you ever need evidence to help prove your claim of copyright ownership (or just need a copy of what you submitted for any other reason), you can ask us to supply a copy of a work you have previously registered.

Forms to do so can be found via: http://copyrightwitness.com/acc/order_dupwork

How we supply duplicate work

As a duplicate work can be used as evidence in a legal claim, it is important that it represents a true, verifiable and accurate copy of the work as it was submitted to us on the registration date.

Duplicate works we produce are supplied with a verifiable, high assurance, digitally signed, manifest that lists the SHA512 hash for each individual file. This means that any files in a duplicate work can be independently verified by comparing the hash of the file with the hash of that file in the manifest.

How does this ensure authenticity?

• The manifest can be confirmed as valid by uploading the digital signature along with the manifest via our verification system at:
  http://copyrightwitness.com/services/workverification
  Successful verification of a manifest means that all information and file hashes listed on the manifest exactly match the files we supplied.
  If a manifest or signature has been altered in any way (e.g. if someone changes a hash to match a different file), the manifest will fail verification.
   
• The authenticity of individual files supplied can be verified by checking the SHA512 hash for a file and checking that against the hash specified in the manifest.
  If a file has been altered in any way the SHA512 hash will not match the manifest.

How does a SHA512 hash work?

A hash is generated by reading the raw file data through a cryptographic algorithm to generate a unique ‘fingerprint’ of the file.

The way a hash is calculated means that even a very small change (e.g. just changing a space or one character) will result in a radically different hash; so it is very clear that the file has been altered when hashes are compared.

The chance of collision (two different files having the same hash) using SHA512 is stated as 1.4×10^77, a truly mind-boggling number (14 with 77 zeros at the end - 1,400,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000).

To put this into context, the number of grains of sand on the entire planet Earth is calculated as 7.5 x 10^18 (75 with 18 zeros); just a mere 75,000,000,000,000,000,000.

Assured evidence

The data included in the manifest and facilities we provide make it possible to verify the authenticity of the duplicate work being presented in evidence.

This means that, if needed, a judge, lawyer, solicitor, arbitrator, etc. assessing your case can check and verify the data for themselves and ensure the accuracy of the evidence you are presenting.

Further information and instructions on how to verify works can be found at:
https://copyrightwitness.com/services/verify-work