Agree, range is not an issue. The trade-off is in battery vs. total time, which would be influenced primarily by the battery sensitivity of the platform. I'll send you a note to follow up.
e On 02/05/2015 05:40 PM, Andy Schroder wrote: > Hello, > > I personally would prefer as low of range as possible for this bluetooth > application considering the connection is not yet encrypted (mentioned > below), and even if it were, it seems like it is always going to be > better in case there is some vulnerability. From my testing with a > bluetooth radio inside my metal cabinet, the range is ~5 meters, which > is more than enough. > > However, the connection is actually a bit slow when the whole > certificate chain is included (~3-4s). You can sort of see this in my > video (http://youtu.be/kkVAhA75k1Y?t=7m39s). A lot of the time is > actually spent verifying the signature, and I'm not sure how much of it > is doing the fetching (I haven't done any detailed timings using "adb > logcat" and looking at the log entries), but I do know it is a little > slower than an HTTPS payment request fetch over wifi (~2-3s). The reason > I know most of the time is the signature verification is because an > HTTPS payment request fetch over wifi and verification using breadwallet > on apple is much faster (<1s) than HTTPS payment request on bitcoin > wallet on android (apparently apple has a significantly more optimized > signature verification algorithm). Bottom line is that there may be ~1s > time transferring the data with this current bluetooth connection. Not > sure how slow it will be with the BLE connection. Time is everything in > a point of sale application. > > So, I guess what I am saying is it seems like the lower speed and range > gain with bluetooth low energy are not a benefit in my opinion. I'm not > sure that the latency gain will be a benefit either unless the speed > issues I am noticing with regular bluetooth are actually a latency issue > with just getting the connection established, or actually transmitting > the payment request data. How much power is going to be used for just a > few second payment? It's not like the bluetooth connection is maintained > for a long time like it may be in other non bitcoin use cases. > > > Where is a more appropriate place to discuss the other issues you have > at length?
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