4 ms·
I would be pretty simple. You use a high-latency channel with "proper" encryption and authentication to stream a one-time pad key; then encryption and decryptio
by perlgeek 12y ago
I would be pretty simple. You use a high-latency channel with "proper" encryption and authentication to stream a one-time pad key; then encryption and decryption would be a simple XOR, plus a bit of synchronization (to know where in the key stream you are). Doesn't sound like it would introduce much latency.
- mindslight 12y agoThat method is missing any sort of message authentication. Knowing the framing, one could easily flip a buy to a sell, etc.
- scott_karana 12y agoOne-time pads are only useful if they're not re-used. Or are you suggesting that the high-latency link is higher throughput, and provides constant gigabytes of pad material? (Eg, stream cipher)
- ah- 12y agoThere is already a second fibre link in these setups that has higher throughput and not much more latency.
- cpwright 12y agoA microwave link is much lower bandwidth than the optical fiber that already exists to connect the two points (you can't rely solely on microwave, you need fiber to back it up when it rains or is cloudy, etc.). Also, depending on the market, you're only trading 8 or so hours a day. You can just send the pad during the 16 hours of the day while the link is otherwise unused.
- aninhumer 12y agoI don't think the one-time pad is necessary here, since the aspect that makes it low-latency is reducing the critical path impact to an XOR at each end. I believe there are various existing encryption schemes which already have this property.