Timestamping and Hashing
- kenshishido
- Jul 11
- 3 min read
Updated: Jul 14
July 10th, 2025 by Ken Shishido, CarHash.io
1: CarHash secures dashcam incident footage on blockchain
You can prove the data authenticity and timestamp with very little cost.
2: The Problem
The reliability of image data extracted from dashcams is under threat.
Case Study 1: (Nagoya, Japan, 2020)
On April 6, 2020, an Aichi Prefecture police in Japan patrol car entered an intersection on a red light as an emergency vehicle, colliding with a civilian vehicle entering on a green light. The civilian driver sued the Aichi Prefecture Police, claiming, “The patrol car wasn’t using its siren.”
The officer driving the patrol car insisted during the investigation that “the siren was on.” The dashcam footage submitted as evidence lacked an audio file, and the Aichi Prefecture Police claimed in their inspector’s report, “The recording function wasn’t used, so no audio file exists.”
However, a judge analyzing the file’s binary data (raw data) pointed out the possibility that the audio portion had been deliberately deleted, which the Aichi Prefecture Police later admitted. (Nagoya District Court, October 5, 2022 ruling)
**References:**
Case Study 2: (Osaka, Japan in 2024)
Tampering with dashcam footage to change a traffic light’s color from “red” to “green.”
“According to Osaka police traffic investigation department, suspect Inokuma allegedly used his computer to alter the traffic light’s color, creating footage that falsely depicted the vehicle ahead stopping at a green light. This was submitted to an insurance company to reduce his own liability.”
Case Study 3: (Georgia, US in 2022)
"The original dash cam recording was several minutes long and included footage from all four cameras. However, the insured altered the video, reducing it to just five seconds and showing only the front-facing view, omitting the other camera perspectives."
We expect similar incidents to occur all over the world in the future.
3: Challenges and Impact
AI advancements make tampering effortless. Once extracted from microSD cards, footage lacks safeguards, diminishing trust in courts and claims. This affects fairness for drivers, insurers, authorities, and manufacturers alike.
4: The Solution
CarHash uses blockchain to timestamp and verify dashcam data authenticity. As a B2B service, we license low-cost functions to dashcam and automotive makers (e.g., ultra low $$/device/year).
Service Overview
Dashcams generate MP4 "incident files" during accidents.
We record the SHA-256 hash (digital fingerprint) on blockchain.
In disputes, verify timestamp and integrity against the original.
What is SHA-256?
A cryptographic hash producing a unique 256-bit value from any data.For manufacturers like Nexar, this builds trust and provides court-admissible evidence (subject to jurisdiction). Insurers gain fraud protection.
Proof of Concept
We've hashed below 1-min MP4 (70MB) and uploaded to blockchain:
Hash: e840c9b599a879b8d3c2318dad93cf1d73c8a84fe51992766fd733d9f4a8dbc0
Transaction ID: 85d8e9e5f1658cf630b6bc819bdee0e05eb9510b368f2c0cffd39d09fe199454 (OP_RETURN field for the Hash value ).
Demo Tool site: (You can try hashing your file onto the blockchain.)
https://timestamped.io/ (provided by Bitails, a blockchain indexer service company which author has a stake, fees covered).
How It Works:
4G Enabled Dashcam detects accident (vibration sensor).
Saves MP4 (~10 min/50MB) to microSD or DashCam cloud server.
Computes SHA-256 hash; sends to CarHash server for blockchain recording (BitcoinSV: ultra-low-cost, highly scalable).
Verify in disputes via lightweight firmware integration.
Note: You can also upload a whole 50M encrypted MP4 file.
6: Market Opportunity
Global dashcam market: over US$4B in 2023 expected to double by 2032).
Targets: Dashcam/Automakers (passenger/commercial vehicles).
Untapped anti-tampering need; potential for industry standard.
Later: Bodycams, connected vehicles (e.g., Toyota T-Connect, Honda Sensing, Tesla, Waymo autonomous driving vehicles).
Insurers: Preferential rates for CarHash-equipped devices.
7: Business Model
B2B licensing (ultra low$$/year/device).
Add-ons: Verification API for insurers; custom for authorities.
Costs: highly scalable.
8: Competitive Advantage
First-mover in blockchain tamper-proofing for dashcam footage
Ultra-low cost, no direct competitors.
Win-win: Enhances trust for all stakeholders.
Partnerships: Seeking exclusive one International and Japanese partners.
9: Traction and Next Steps
Prototype: Completed (PoC success). MVP to be completed by end of 2025.
Discussions: Ongoing with various companies.
10: Strategic Partnership Invitation
As one of the leading companies in DashCam, your expertise in dashcam innovation aligns perfectly. We're seeking one international partner for MVP co-development and strategic alliance. Let's collaborate to set the standard—contact me at ken@carhash.io to discuss.
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