Quote from: h0lybyte on September 17, 2014, 12:35:21 AM

I think your logo is pretty dope

Do you guys have an IRC channel?

Thank you! We also think that it is very nice.
We don't have an IRC channel by now, but I will look into the matter.

Quote from: sussex on September 17, 2014, 12:55:44 AM

I've just read your lock and key whitepaper and have some questions.......

Good questions, so lets begin answering them.

Quote from: sussex on September 17, 2014, 12:55:44 AM

A discrete MCU with both Bluetooth and cellular chipsets and antennas is going to be far too big for mobile phones, MP3 players and many laptops, so we are presumably talking about larger household electronics - TVs, HiFi etc in this context?

The technology and engineering involved in that is more flexible and miniturized than it might appear at first glance. First, there is no need to use seperate antennas for bluetooth and cellular communication. Both work on the basis of radio frequency and in bands far apart. It should even be possible to use both at the same time using the same antenna, even though that should not be necessary. Also, seperate chips for both bluetooth and cellular communication are convenient, but ultimately not necessary. The development gets more complicated this way, but the final goal is a chip which is specifically tailored for the task.
When it comes to size, you are right about the MP3 player. Most likely such a device is too small by itself to house one of our locks. On the other hand... MP3 players are not really a large market anymore, they are usually integrated in smartphones. Those on the other hand have the trend of getting slightly larger as time passes. As the lock will soonest be ready with the next generation of smartphones, size should not be a serious problem anymore.
If all of this does not convince you, take a look at this

http://www.samsung.com/uk/consumer/mobile-devices/mobile-phones/bar/GT-E1200ZKABTU

This classic mobile contains everything needed for the lock. Take away display, housing, battery and keys and there is not much left. Also, the technology used there is slightly dated already. It was released in 2011. So in conclusion, we don't see any problems with the size of the lock in any case but MP3 players and smartwatches.

Quote from: sussex on September 17, 2014, 12:55:44 AM

If there is a need to use the cellular network, won't it be necessary for each device to have a contract/pay as you go deal with a mobile phone operator? A sim card will also be necessary?

A sim card is not necessary to transmit data over the cellular network. It is only used for phone calls and text messages. Technically it is not even required there. The data requirements for the lock will need to be taken care of by the company selling the locks. Hopefully us of course. As data transmission costs about about 5 Dollar-cents per gigabyte, we also don't see a big problem if this handled on a company to company basis.
Nevertheless, we will look further into the matter to see if there is any convenient way to make the whole thing fire and forget for every party involved. The underlying cryptocurrency might offer solutions in that regard.

Quote from: sussex on September 17, 2014, 12:55:44 AM

If I lose the key, the device shuts down?

After a grace period configurable by the user.
You will surely have more questions in that regard though. As a preemptive try to answer them:
Transactions will always be multi signature. A single private key of the multi signature transaction will be enough to unlock a device. More than one will be needed to create a new transaction. Loss of the key thus does not mean loss of ownership of all devices.
You will need to buy a new key though when you lose yours.

Quote from: sussex on September 17, 2014, 12:55:44 AM

If I have a laptop with the MCU embedded I also need to remember to take the key when mobile? In this scenario, a TV that I leave at home would need it's own separate key?

Grace periods for all devices may be set. If you want to use a single key and maybe don't even have it with you all the time, set your devices to 24h plus grace periods. You want more security and immediate reactions in case of theft. 3 minute grace period is enough. Get it stolen and it stops working almost immediatly. Correct set grace periods will allow for usage of a single key. Multiple keys might be more convenient though.

Quote from: sussex on September 17, 2014, 12:55:44 AM

On the subject of the key, how long will a charge last? Battery capacity is directly related to it's physical size.

Correct. A final design is not ready of course, but we target a battery lifetime of approximately 48 hours. Prefferably more. Of course, this will also depend on some of the user settings. The more frequent the security feature is used and with more range, the shorter the time until next recharge will be.

Quote from: sussex on September 17, 2014, 12:55:44 AM

I understand that in the context of mobile phones you will be able to utilise the radio chipsets already built into the handset, but you will still have to carry the key or specify a when the next check is made and hope you are in the vicinity of the key at that time?

Yet again, the grace period will take care of that. If a check is failed, the device will not necessarily shut down immediatly. If grace periods are set to a long time, carrying of the key will not be necessary. If you lock your door with our key you might want to take it with you though

I hope this answers your questions to your satisfaction.