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There's already a process for this, its called chain of custody. If you cant prove the evidence has a solid chain of custody then it was potentially tampered wi

There's already a process for this, its called chain of custody. If you cant prove the evidence has a solid chain of custody then it was potentially tampered with and isn't reliable.

LPisGood 2y ago
This is unironically a usecase for blockchain.
- adiabatichottub 2y ago
  Who needs a whole blockchain? Just basic public-key cryptography would do the job. Imagine if you will, that the NVR (recording system) has a unique private key flashed in during manufacturing, with the corresponding public key printed on it's nameplate. The device can sign a video clip and its related meta-data before exporting. Now, any decent hacker could see possible holes in this system, but it could be made tamper-resistant enough that any non-expert wouldn't be able to fabricate a signed video. Then the evidence becomes the signed video and the NVR's serial number and public key. Not perfect, but probably good enough.
  - hippari2 2y ago
    Unfortunately consumer devices often have weak cryptography built into them. The one properly implemented are just out of reach for average consumer.
- CMCDragonkai 2y ago
  More than just a blockchain, you need a decentralized set of oracles to mutually corroborate information. https://polykey.com/blog/ai-detection-versus-cryptographic-provenance https://polykey.com/blog/ai-detection-versus-cryptographic-p...
mrandish 2y ago
Yep, "chain of custody." Came here hoping to see that concept discussed since it's how the system already deals with cases of potential evidence tampering. If the evidence is of material importance and there's no sufficiently credible chain of custody, then its validity can be questioned. The concept started around purely physical evidence but applies to image, audio and video. The good thing about the ubiquity of deepfake memes on social media is that it familiarizes judges and juries with how easy it now is to create plausible fake media.
- dragonwriter 2y ago
  Chain of custody only covers from when the evidence came into the hands of the police; the real issue here is original provenance, which chain of custody doesn't solve. Evidence of provenance is already important, to be sure, but the the ability to have some degree of validation of the contents has itself provided some evidence of provenance; lose that and there is a real challenge.
AnthonyMouse 2y ago
The usual chain of custody goes something like: The store has a video surveillance system which the police collect the footage from, so the chain of custody goes through the store and the police which implies that nobody other than those two have tampered with it. But then you have an inside job where the perpetrators work for the store and have doctored the footage before the police come to pick it up, or a corrupt cop who wants to convict someone without proving their case or is accepting bribes to convict the wrong person and now has easy access to forgeries. Chain of custody can't help you in either of these cases, and both of those things definitely happen in real life, so how do you determine when they happen or don't?
- iamacyborg 2y ago
  Surely chain of custody applies if the accused has access to the evidence? Perhaps I’m missing your point or I’m overly optimistic about the legal system.
  - AnthonyMouse 2y ago
    Suppose the store manager is having a dispute with a kid who keeps skateboarding in the parking lot, so the store manager decides to commit insurance fraud by robbing the store herself and then submits forged video of the kid doing it to the police. The store manager is in the chain of custody but isn't a suspect, the accused is the kid. The kid doesn't even know who actually committed the crime. How is the kid supposed to prove this?
    - condiment 2y ago
      In this case, chain of custody needs to extend to the capture device itself, and to any software that exists in the supply chain for the video content. There are some experimental specifications that exist to provide attestation as to the authenticity of media. But most of what I’ve seen so far is a “perjury based” approach that just requires a human to say that something is authentic.
      - 2y ago
_DeadFred_ 2y ago
This is such BS. The government is ALWAYS deferred to when the chain of custody is broken because 'good faith' is applied. As long as 'good faith' is rountely dispensed 'chain of custody' is nothing but propaganda for the justice system not an actual tool used for justice. As long as chain of custody ca be discarded because 'good faith' whenever it becomes inconvenient it is not a real thing.

There's already a process for this, its called chain of custody. If you cant prove the evidence has a solid chain of custody then it was potentially tampered with and isn't reliable.

LPisGood 2y ago

This is unironically a usecase for blockchain.

adiabatichottub 2y ago
Who needs a whole blockchain? Just basic public-key cryptography would do the job. Imagine if you will, that the NVR (recording system) has a unique private key flashed in during manufacturing, with the corresponding public key printed on it's nameplate. The device can sign a video clip and its related meta-data before exporting. Now, any decent hacker could see possible holes in this system, but it could be made tamper-resistant enough that any non-expert wouldn't be able to fabricate a signed video. Then the evidence becomes the signed video and the NVR's serial number and public key. Not perfect, but probably good enough.
- hippari2 2y ago
  Unfortunately consumer devices often have weak cryptography built into them. The one properly implemented are just out of reach for average consumer.
CMCDragonkai 2y ago
More than just a blockchain, you need a decentralized set of oracles to mutually corroborate information. https://polykey.com/blog/ai-detection-versus-cryptographic-provenance https://polykey.com/blog/ai-detection-versus-cryptographic-p...

mrandish 2y ago

Yep, "chain of custody." Came here hoping to see that concept discussed since it's how the system already deals with cases of potential evidence tampering. If the evidence is of material importance and there's no sufficiently credible chain of custody, then its validity can be questioned. The concept started around purely physical evidence but applies to image, audio and video. The good thing about the ubiquity of deepfake memes on social media is that it familiarizes judges and juries with how easy it now is to create plausible fake media.

dragonwriter 2y ago
Chain of custody only covers from when the evidence came into the hands of the police; the real issue here is original provenance, which chain of custody doesn't solve. Evidence of provenance is already important, to be sure, but the the ability to have some degree of validation of the contents has itself provided some evidence of provenance; lose that and there is a real challenge.

AnthonyMouse 2y ago

The usual chain of custody goes something like: The store has a video surveillance system which the police collect the footage from, so the chain of custody goes through the store and the police which implies that nobody other than those two have tampered with it. But then you have an inside job where the perpetrators work for the store and have doctored the footage before the police come to pick it up, or a corrupt cop who wants to convict someone without proving their case or is accepting bribes to convict the wrong person and now has easy access to forgeries. Chain of custody can't help you in either of these cases, and both of those things definitely happen in real life, so how do you determine when they happen or don't?

iamacyborg 2y ago
Surely chain of custody applies if the accused has access to the evidence? Perhaps I’m missing your point or I’m overly optimistic about the legal system.
- AnthonyMouse 2y ago
  Suppose the store manager is having a dispute with a kid who keeps skateboarding in the parking lot, so the store manager decides to commit insurance fraud by robbing the store herself and then submits forged video of the kid doing it to the police. The store manager is in the chain of custody but isn't a suspect, the accused is the kid. The kid doesn't even know who actually committed the crime. How is the kid supposed to prove this?
  - condiment 2y ago
    In this case, chain of custody needs to extend to the capture device itself, and to any software that exists in the supply chain for the video content. There are some experimental specifications that exist to provide attestation as to the authenticity of media. But most of what I’ve seen so far is a “perjury based” approach that just requires a human to say that something is authentic.
    - 2y ago

_DeadFred_ 2y ago

This is such BS. The government is ALWAYS deferred to when the chain of custody is broken because 'good faith' is applied. As long as 'good faith' is rountely dispensed 'chain of custody' is nothing but propaganda for the justice system not an actual tool used for justice. As long as chain of custody ca be discarded because 'good faith' whenever it becomes inconvenient it is not a real thing.