News that Helium, which operates one of the largest networks based on the LoRaWAN low power WAN protocol, has started rolling out in Europe after extending to over 1,000 cities in North America, provides a good chance to assess the value and impact of its underlying blockchain technology on the IoT more widely.
This comes at a time when blockchain has been enveloped in fake news concerning its possible contribution to future pandemic tracking in the light of the ongoing Covid-19 coronavirus crisis. Blockchain advocates have been prone to oversell its benefits, especially the idea that it could have nipped Covid-19 in the bud and stopped global transmission in its tracks.
Laughable claims aside, this is not to say blockchain will not play a valuable role in future global pandemic response networks, but it would more be for oiling the machinery than fundamentally changing the efficacy and pace of monitoring actual or potential respiratory viruses from zoonotic sources into the community. It would be AI and machine learning, if anything, that advance the game more substantially by helping identify unusual trends indicative of an incipient pandemic earlier.
Helium’s blockchain, called LongFi, underpins its so-called ‘people’s network’. The example allows scrutiny of the technology’s benefits, as well as limitations or challenges. As we know, blockchain first came to widespread attention for its role in cryptocurrencies and especially bitcoin, which called for a distributed security technology that was highly resistant to tampering and allowed robust immutable recording of transactions in a scalable way.
Blockchain is a distributed database or ledger, so called because it comprises multiple records or ‘blocks’, linked or ‘chained’ together via cryptographic processes designed to resist tampering rather than eavesdropping. Each successive block is a mash-up or hash of the one before it using strong public key cryptography, implemented with a decentralized approach designed to confer scalability.
This can support many use cases but always with each new block containing a reference to the previous one, creating chains that confer the transparency as well as immutability essential for cryptocurrency operations, where being resistant to alteration is about the most important property.
This all comes at the expense though of simplicity, since large blockchains are highly complex and computationally intensive to create and operate. The computation is performed by distributed machines called miners, which create the blocks. Many potential vulnerabilities of blockchains are not surprisingly associated with miners and their organization, although some of these apply mostly to dedicated cryptocurrency networks rather than general IoT cases. Indeed, blockchain is often hyped as a panacea for IoT security problems.
It is not a panacea of course, and should best be regarded as an enhancement to existing IoT security rather a standalone solution. It is an extra layer that can be applied to strengthen existing procedures, which admittedly are often weak on their own.
As indicated, the main security addition conferred by the blockchain layer is the immutability, the resistance to tampering that solves the trust issue, because no single entity has control over all the data generated by a constellation of IoT devices. The strong encryption makes it very hard to overwrite existing records. Here blockchain can actually reduce the need for security processing by other components such as IoT gateways, by handling the chain of trust on its own.
The ability to coordinate massive numbers of devices in a scalable way, so that processing overhead only increases almost linearly with the IoT population, is also a strength. But we should beware of claims that blockchain can reduce overall computational cost. It merely transfers that cost from other parts of the IoT firmament, such as the gateways, into the blockchain infrastructure.
In fact, the high computational overhead of blockchain renders it unsuitable for IoT applications that require ultra-low latency, or even probably quite low latency. It certainly makes it impossible to guarantee low delay and would counteract those efforts spanning both wired and wireless communications, such as time sensitive networking (see separate item on WiFi 7) to establish predictable latencies over previously indeterminate systems like Ethernet.
The Helium LoRaWAN blockchain-based network can be seen in this context, being aimed at applications where both computational, storage and network bandwidth overheads are light. It is a service that avoids the need for deployment of gateways or servers by customers, where transactions are recorded and stamped with relevant indicators including connectivity time and location, being immutable and yet readily accessible or inspectable. The network was established with help from provider of LoRaWAN networking technology Semtech, as well as LoRa device maker Cal-Chip Connected Devices, part of a distributor called Cal-Chip Electronics.
The network has already attracted 8,000 developers, according to Helium, including GPS hardware developer Digital Matter, IoT monitoring firm Conserv, security software and hardware firm Smart Mimic and agritech provider Agulus. These represent the sort of use cases for which LoRaWAN and blockchain are well suited within the IoT realm.
Asset tracking enabled by Digital Matter seems especially fertile ground for this approach, capturing and storing location and movement history data for protection and recovery of assets, such as pallets, containers, equipment, vehicles, trailers and bins. Admittedly this is not quite the cutting edge of IoT, but is an area where real benefits and cost savings can be obtained.
There are also some consumer cases here, such as dog tracking, where chips that the company calls Helium Tabs would be inserted on the collar say and would feedback location data via the LoRaWAN network. WiFi would not cut it because its coverage is too patchy, while cellular would cost too much. The same approach could be used for cats or for that matter purses.
It is worth pointing out that the firm has harnessed the blockchain model for recruiting computational capacity and created incentives with resource providers able to earn ‘Helium’ as a cryptocurrency. This is how the blanket coverage is achieved, with individual hotspots able to cover up to 10 square miles (25 square kilometers).
Blockchain then has potential for the many small or low value transactions that will be generated in both the consumer and enterprise IoT sphere. But users should still beware of overhype.