This is actually one of the very few reasonable use cases for block chain technology.
You have a security camera on site. It takes recordings and sends them to a data centre which then appends the footage and uses various algorithms to make a much smaller block chain compatible summary, a small hash for each snippit of video. The hash is then mixed with the previous sum of all hashes and appended to the video. This means that after the fact modifying the video is effectively impossible. You would have to do it between the camera and the data centre, so yes, still possible, but doing it at a later date would be very hard. You could also make sure this data was stored in an append only form, say magnetic tape, which has physical measures to prevent access after the date of storage.
Technically, yes, if you have access to the system, but it does mean you have to switch the storage from append only to read write, then pull out the original files, recompute the hashes from the time you did the modifications, and do all the rewriting as you go. For a continuous thing like this your security is only as good as the weakest link, so you could have a problem there, but publishing or sharing the hashes as you go could further protect in this situation. If others have the hashes and then some of them change we know there was a change of data. Add or change something and every hash from then on is different. Seems plausible to make it much better than take my word.
This is actually one of the very few reasonable use cases for block chain technology.
You have a security camera on site. It takes recordings and sends them to a data centre which then appends the footage and uses various algorithms to make a much smaller block chain compatible summary, a small hash for each snippit of video. The hash is then mixed with the previous sum of all hashes and appended to the video. This means that after the fact modifying the video is effectively impossible. You would have to do it between the camera and the data centre, so yes, still possible, but doing it at a later date would be very hard. You could also make sure this data was stored in an append only form, say magnetic tape, which has physical measures to prevent access after the date of storage.
You are forgetting the simplest form of fucking with this, hijack the feed.
No, it was explicitly called out as a flaw:
Recomputing the hashes is not a problem at all.
Technically, yes, if you have access to the system, but it does mean you have to switch the storage from append only to read write, then pull out the original files, recompute the hashes from the time you did the modifications, and do all the rewriting as you go. For a continuous thing like this your security is only as good as the weakest link, so you could have a problem there, but publishing or sharing the hashes as you go could further protect in this situation. If others have the hashes and then some of them change we know there was a change of data. Add or change something and every hash from then on is different. Seems plausible to make it much better than take my word.
Hi. There are thousands of ways to fuck with this.
Don’t anger the tech bros! /js