The British Ministry of Justice has wrote a blog post to explore the use of blockchain within its jurisdiction. It wanted to show how Distributed Layer Technology (DLT) could improve government systems, especially in situations where public trust of government might not be taken for granted.
So they have, obviously, “stumbled” on criminal prosecutions, in which digital evidence such as documents, emails, and video footage is more and more important. In that sense, a system could be developed to make sure that procedures and mechanisms for verifying the integrity of the evidence are kept up to date and appropriate for a modern digital society.
An example system
It is not hard to envision a near future in which every police officer will carry a video camera that records evidence throughout their shift. Such setup could easily produce petabytes of data every day, and needless to say — all this data would need to be stored, managed, catalogued, and made retrievable. And that’s where blockchain kicks in.
A system could be developed to enable each officer to plug their video camera into a device which splits the recorded footage into small chunks — say, 10 minutes per chunk — and uploads each chunk to a secure cloud service.
From there the service performs several functions:
- Provides secure cloud storage and controlled access
- Records metadata about each clip — which device it was from, where and when it was shot, etc.
- Calculates a hash of the clip and of the metadata, creating a unique hash (identifier) for every video.
- Records the hashes of the clip and its metadata onto a blockchain. Videos themselves would not be on the blockchain, just a hash of their data and metadata, including a pointer to each video’s location in the secure storage service.
This blockchain would be readable by anyone, but only writable by the police, creating a verifiable record of data about each video. Then, if some video is ever needed in court, it could be unambiguously, cryptographically verified that the chunk of video seen in court is exactly identical to that particular chunk recorded at that time, and has not been altered or processed in any way.
Technology you can trust…
Where processing is needed, for instance to enhance clarity, hashes of the processed clip could also be logged on the blockchain. The original source footage could then be compared to demonstrate that the processing has not been excessive or introduced unreasonable artifacts.
As the blockchain is distributed, even the most ardent conspiracy theorists could verify for themselves that the evidence has not been tampered with — there could be no possibility of records being falsified after the fact without detection.
Still a thought experiment…
UK’s Ministry of Justice notes that at this stage this is still a “thought experiment,” and there are many hurdles to overcome for a real-world implementation. But the possibilities are there, nonetheless. Blockchain could transform finance, government and society as a whole.
The Ministry also added that similar ideas are being explored at the Home Office, with other investigations into DLT applications including areas such as secure diplomatic messaging. They call this the “Blockchain of Evidence.” We like it… a lot. 😉