3 ms·

you wouldn't need to use their website and the service would be completely decentralized. the website has the exact same problem that you pointed out for the b

by itake 5y ago

you wouldn't need to use their website and the service would be completely decentralized. the website has the exact same problem that you pointed out for the blockchain: you can screen capture a QR code and re-use it later.

ricardobeat 5y ago
No, you can’t. It’s one of the main features, explained right there in the page.
- itake 5y ago
  > It does not work against the past (taking snapshots of the code and using them later) Right on the page, it says this. Maybe I am not understanding your point. Both the website and the blockchain strategy make it impossible for you to record video content and claim it happened in the future, but neither of them defend against recording after the timestamp happened. The blockchain strategy does not require a centralized service, while the QR code requires the website to be up forever.
  - miunau 5y ago
    You can always use the published public key to verify the signature. There's also a way to generate the codes offline using a certificate chain and a fingerprint (https://github.com/qrdate/qrdate#static-qr-date-v1-spec https://github.com/qrdate/qrdate#static-qr-date-v1-spec) which does not require a website, just a key store. It needs more specifying to be viable for real world use but it should be possible. Help is very welcome.
    - itake 5y ago
      If you print out a piece of paper with the latest block, hold up the NYT's, or use your service, you still only prove that the content was created after a certain date. AFAIK, signing off a timestamp and offering a public key to prove the timestamp was signed then doesn't seem to add value other than unnecessary complexity. I guess if there is a specific time you're trying to prove the event happened after, this system would offer higher fidelity than others, but not all.

3 ms·

you wouldn't need to use their website and the service would be completely decentralized. the website has the exact same problem that you pointed out for the b

by itake 5y ago

ricardobeat 5y ago
No, you can’t. It’s one of the main features, explained right there in the page.
- itake 5y ago
  > It does not work against the past (taking snapshots of the code and using them later) Right on the page, it says this. Maybe I am not understanding your point. Both the website and the blockchain strategy make it impossible for you to record video content and claim it happened in the future, but neither of them defend against recording after the timestamp happened. The blockchain strategy does not require a centralized service, while the QR code requires the website to be up forever.
  - miunau 5y ago
    You can always use the published public key to verify the signature. There's also a way to generate the codes offline using a certificate chain and a fingerprint (https://github.com/qrdate/qrdate#static-qr-date-v1-spec https://github.com/qrdate/qrdate#static-qr-date-v1-spec) which does not require a website, just a key store. It needs more specifying to be viable for real world use but it should be possible. Help is very welcome.
    - itake 5y ago
      If you print out a piece of paper with the latest block, hold up the NYT's, or use your service, you still only prove that the content was created after a certain date. AFAIK, signing off a timestamp and offering a public key to prove the timestamp was signed then doesn't seem to add value other than unnecessary complexity. I guess if there is a specific time you're trying to prove the event happened after, this system would offer higher fidelity than others, but not all.