2 ms·

> at a given date and time *after a given date and time There's nothing stopping people forging the data later with already broadcast cryptographic signatures

XorNot 5y ago
That's the idea of using the low orbit constellations - obviously this doesn't work if you're just passively recording a broadcast, it has to be 2-way - which rules out anything not designed for that. But low-orbit satellite internet is designed for 2 way communications, and probably already has the equipment on board to calculate checksums (or at the very least is a sufficiently trusted third party). So we develop a protocol we can run on miniaturizable boxes which can be served point-to-point with the constellation members to at least prove transmission origin providence.
- Grimburger 5y ago
  How do you trust the satellites without them all being controlled by a central authority? It's the Byzantine Generals problem.
  - ethbr0 5y ago
    In this scheme they would be controlled by a central party, as effectively we're talking about Starlink and SpaceX. Or maybe one of the legacy satellite internet providers. Assuming that though, you send a hash of your content up to the system, which geolocates it (based on physical reception), adds a timestamp and geolocation into the metadata, and returns the signed information, using the central party's key. You also could run a similar method on cellular networks by using towers as the signing node and the telecom as the centralized entity. Because realistically, it's not Byzantine Generals. What you want is (a) timestamp verified by a trusted party, (b) geolocation verified by a trusted party, (c) content hashed/signed to prevent subsequent modification, (d) prevention of replay forging of (a) or (b), & (e) most of the infrastructure not physically accessible by users (e.g. signing chip embedded in a camera).

XorNot 5y ago

That's the idea of using the low orbit constellations - obviously this doesn't work if you're just passively recording a broadcast, it has to be 2-way - which rules out anything not designed for that. But low-orbit satellite internet is designed for 2 way communications, and probably already has the equipment on board to calculate checksums (or at the very least is a sufficiently trusted third party). So we develop a protocol we can run on miniaturizable boxes which can be served point-to-point with the constellation members to at least prove transmission origin providence.

Grimburger 5y ago
How do you trust the satellites without them all being controlled by a central authority? It's the Byzantine Generals problem.
- ethbr0 5y ago
  In this scheme they would be controlled by a central party, as effectively we're talking about Starlink and SpaceX. Or maybe one of the legacy satellite internet providers. Assuming that though, you send a hash of your content up to the system, which geolocates it (based on physical reception), adds a timestamp and geolocation into the metadata, and returns the signed information, using the central party's key. You also could run a similar method on cellular networks by using towers as the signing node and the telecom as the centralized entity. Because realistically, it's not Byzantine Generals. What you want is (a) timestamp verified by a trusted party, (b) geolocation verified by a trusted party, (c) content hashed/signed to prevent subsequent modification, (d) prevention of replay forging of (a) or (b), & (e) most of the infrastructure not physically accessible by users (e.g. signing chip embedded in a camera).