- From: Drasko DRASKOVIC <drasko.draskovic@gmail.com>
- Date: Wed, 31 Aug 2016 22:13:13 +0200
- To: "Tibor Z. Pardi" <tibor@zovolt.com>
- Cc: Dave Raggett <dsr@w3.org>, Public Web of Things IG <public-wot-ig@w3.org>
Hello, On Tue, Aug 30, 2016 at 8:06 PM, Drasko DRASKOVIC <drasko.draskovic@gmail.com> wrote: > This is very kind of you. I will give you a call, an then re-paste > here the meeting minutes. I had extremely interesting Skype meeting with Tibor who was very kind (and patient :)) to explain me lot of things about his Blockchain visions and how they propose the solution in Streembit project (http://streembit.github.io/). As promised, here are (quick and dirty) meeting minutes (more in the form of Q&A): [Q] Blockchain is distributed ledger. How do you stock the list of transactions in IoT network, having in mind that is it comprised of highly constrained low-power devices [A] Full Bitcoin node can reach today 90GB. Even on PC this becomes impractical. Partial solutions are trusted nodes. **Only gateways** store data in DHT - gateways are powerful nodes - RPi can have this role for the demo. Devices behind the gateways do not run Kademlia DHT. [Q] What are the benefits of decentralization if you have "partialy decentrlaized" network, i.e. some kind of private subnets? [A] There are many - some are described here: http://streembit.github.io/2016-03-02-Internet-of-Things/ and here: http://streembit.github.io/2016-07-15-Streembit-IoT/ - like device discovery, distributed storage for firmware update, etc. Price is lowered dramatically (no centralized expensive infrastructure). Security is equally important, as centralized server is a target for hackers, industrial espionage, etc - we are distributing the risk. [Q] Do we need Blockchain at all? DHT is enough for device discovery. [A] We need some kind of distributed ledger as we need certifications and device audits. Simple merkle tree ahould do the job. [Q] About the storage of messages needed for data analytics, machine learning, big data... Is it distributed now? [A] Yes - this also - beside identity management - is the role of DHT - it keeps distributed storage of all historical messages (can be set per node, etc). [Q] What about micro-transactions - do they make sense? Like machine A buying service from machine B? [A] Experiences tell that this is not really feasible at this moment. Should not be neglected though. But challenges are huge - Bitcoin has delay of 10-15 min (6 blocks must be processed). Ethereum about 40-50 sec. But for IoT we need **instant** transactions (and for sure all centralized solution like PayPal, Visa, Google, Apple - all of them can allow this). This is practically impossible to solve with current Blockchain. Other big problem is 51% or Byzantine Generals attack (this is where the delay comes from in the first place) - how will we protect the network. Tibor, I have surealy forgotten or misinterpreted something, so please feel free to correct. Thank you again very much for your time and clarifications. Best regards, Drasko
Received on Wednesday, 31 August 2016 20:13:43 UTC