Great Britain’s Ministry of Justice technical architecture lead, Alistair Davidson, has claimed that Blockchain or distributed ledger technology (DLT) has great potential as a tool for securing and verifying digital evidence in a criminal investigation. He specifically cited the use of the technology in the creation of records for officer-worn camera footage.

In a blog post published in early November 2017, Davidson detailed how Blockchain can be used in law enforcement, particularly in establishing records for footage taken from cameras worn by police officers. He claimed that the prosecution can use the ledger record to prove the authenticity of the videos during court trials.

"This property of distributing trust could be genuinely transformational in situations where public trust of government might not be taken for granted."

Securing digital evidence

In his explanation, Davidson claimed that the ledger would not be used to store the footage, but it would contain a hash of the video’s data and metadata as well as a listing of its location within the storage area used by the government.

He further explained that if the videos are uploaded to a publicly available cloud storage, the Blockchain can be read by any user at any place, but only the police can be able to write additional information in it.

Meanwhile, the Ministry of Justice has explained in a published technical overview that despite its immutability, a Blockchain can only verify assets that are stored in it after they are listed. Files could still be changed or modified prior to being listed on the Blockchain.

“At a given moment (according to the Blockchain timestamp), this digital asset existed in precisely this form. We can also identify the organization/person who wrote the digital fingerprint to the Blockchain. We cannot say that the digital asset has never been tampered with or falsified - only that it has not been altered since its fingerprint was generated.”

This is not the first case where Blockchain is used in criminal investigations. In fact, the FBI used cryptocurrency to solve a murder case earlier this year.