3 ms·

But isn't this trivially susceptible to a relay attack? Anyone could capture the IR sequences that cause the band to light up in each color, and rebroadcast the

• bobmcnamara 2y ago
  > Anyone could capture the IR sequences that cause the band to light up in each color, and rebroadcast them whenever they want. Add a monotonic counter/nonce > But I think we're in agreement that this is pointless anyway... Agreed.
• deleted 2y ago
  [deleted]
• kelnos 2y ago
  They certainly could do that, but: 1. Most people at this sort of concert want things like this to work. I don't think there are many people who are going to buy a ticket to go just to screw with the LED wristbands. Then again, who knows, some people are unfathomably stupid. 2. It would be fairly difficult to sneak a 30W IR lamp into the concert undetected. I suppose you could do something (much) smaller and low power; maybe disguise it as a phone or a point-and-shoot camera (which concert security may or may not allow), but then you're not going to affect all that many devices. And it also might not be hard for security to find you if they can see some sort of radius of effect from where you're standing. You'd probably have to hold it up in the air, continuously, for a while.
  • Wowfunhappy 2y ago
    Right, which is why I've been saying there's no point encrypting any of this!