This article is from:infoq,author:hologram ，This article is from:
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Translation: Wang Qiang, forwarded with authorization.
The term "blockchain" can get annoying too often. Although the messy blockchain ICO environment has fueled people's doubts about the blockchain, it is normal for such doubts to appear every time a disruptive technology appears. In fact, doubt itself may be a booster for emerging technologies. When the hype period of a new technology is over and people's expectations are dashed, it is the feedback of the skeptics that makes the technology advance and reborn.https://www.cryptokitties.co/So here comes the question: Which blockchain project can serve the current IoT practice scenario?
), is there any decentralized network platform now that could become the architecture of choice for IoT data transmission in the next 12 to 18 months?
Below is a comparison of some of the most promising decentralized IoT platforms, either already available or in alpha or beta testing.
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Typical IoT SolutionsMQTT BrokerOne of the most commonly used data transfer protocols for IoT devices is MQTT. It uses a server/client message queue architecture, using a publish and subscribe model. MQTT needs a central manager named Broker. It is the only source of trust for the system.The logic of MQTT is simple. The central Broker of this architecture receives data from multiple data publishers, and then forwards the data to any number of subscribers. In addition to being used as a message queue, MQTT Broker also supports authentication, up to 3 levels of QoS, and the ability to filter data by topic. MQTT was originally born in 1999, and then fully developed by IBM until it was open sourced in 2013. Today there are many practicalproject and
MQTT client library
, what you can do is up to your imagination.
Many commercial IoT platforms use MQTT as the backbone. The flexibility of MQTT allows enterprises to deploy large numbers of IoT devices that are constantly publishing data, while deploying any number of servers to subscribe to pre-filtered raw data.https://www.gartner.com/newsroom/id/3598917Here are the MQTT platforms most commonly used by our customers: AWS IoT, Google Cloud IoT Core, Azure IoT Hub, Losant, and Adafruit IO.
In this article, MQTT will be used as a benchmark for comparison with blockchain and distributed ledger technologies.
Definition of Blockchain
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Definition of Blockchain
A blockchain is an immutable decentralized ledger that can be thought of as a new kind of database. The fundamental core of the blockchain is a shared ledger that is updated across the entire network of nodes. Each node is a device that receives and verifies a copy of the ledger. Data is stored on the ledger in chronological order, and new data is added to the ledger and propagated throughout the network. The data held by the ledger can record transactions, documents, files or other valuable content.
Because each new block contains the hash of the previous block, if someone tries to change the data at any point on the chain, the result will be a change in the hash that cannot be verified by other nodes. So mixing tampered data into the network is practically impossible. In order to change the data on the chain, you need to access every copy of the ledger in the world, and also change their content at the same time. No one person or organization can gain that much power, making blockchain a system of trusted transactions or identity verification that doesn't require a central source of trust.
We want a self-validating, massively distributed database of secure user accounts, transactions and reliable validation. This need has not been possible in the past, so we created the Federal Insurance Bank.
IoT solution based on Ethereum blockchainEthereumThe general public may learn about blockchain technology through Bitcoin, but developers learn about blockchain through
Ethereum
, and the latter has therefore become the most practical blockchain platform. Ethereum allows developers to create their own decentralized contracts that define rules, functions, and even a new digital currency.
Remember the ICO mania of 2017? Ethereum provides tools that enable tech entrepreneurs to create their own cryptocurrencies. The ease with which developers can create their own cryptocurrencies is what makes the Ethereum ecosystem, developer community, and Ethereum blockchain.https://github.com/ethereum/casper/releases）。
The computing power requirements and storage requirements of traditional blockchains such as Bitcoin and Ethereum are too high to be used for IoT devices. For example, typical Ethereum nodes use GPUs to process blocks because CPUs are too slow; each node also stores nearly 1TB of blockchain history transaction data. As Ethereum itself admits, it is slower, more expensive, and more power-hungry than centralized cloud services. In order for the blockchain to become an optional data transmission platform, consensus time-consuming and mining costs must be greatly reduced.Ethereum's leadership team did not ignore these issues. For years, the core developers have been working on a project called Casper. Casper changes the consensus mechanism of blockchains from a computationally intensive operation called "Proof-of-Work" to a risk-based operation called "Proof-of-Stake". Casper will have a major impact on the Ethereum market. This change is something to look forward to for IoT projects, as it will reduce transaction processing costs and enable less powerful devices to confirm blocks. In May, the Casper team released version 0.1.0, which was updated to 0.2.0 a week later (In January, the Ethereum Foundation announced two
subsidy program
To further address scalability issues, developers participating in candidate programs can receive grants of $50,000 to $1,000,000 or more. Specific to the candidate schemes, the Foundation has given two strategies and hopes that the community will advance in parallel. They are blockchain sharding and two-layer protocols.
Two-layer protocols are often referred to as sidechains. These sidechains borrow many features from Ethereum and create an independent chain that enables many data transactions to be processed off the Ethereum chain. Finally, the side chain will upload all transaction records to the Ethereum main chain.RaidenandPlasma。
and
With so many Ethereum-based projects and developers working on solving scalability issues, the combination of Ethereum and sidechains may soon become a popular alternative to the traditional message queue + database architecture.
secondary titleIPFSIoT solution based on IPFS
An exciting, practical implementation of distributed ledger technology is the Interplanetary File System (
). IPFS creates a distributed file system among independent nodes. IPFS can be used to host websites, files and even videos.https://ipfs.io/ipfs/QmNhFJjGcMPqpuYfxL62VVB9528NXqDNMFXiqN5bgFYiZ1/its-time-for-the-permanent-web.htmlAn IPFS node only stores the content that the node is interested in and an index of the stored content. This differs from traditional blockchains, which require each node to locally store the entire network's transaction history. There may be many differences between IPFS and traditional blockchains, but the similarity is that the encrypted hash value of the file is stored on multiple nodes in the network.
Someone called on everyone to use IPFS (
), the reason given is extremely ambitious: if the entire network uses IPFS to replace the centralized HTTP server, then the network world will become a better place. If the hash address is known, then each client node can access the entire file network. The client node can decide whether to store the hash data, and the node storing the data will become the host node of this data. Even if a node storing data is disconnected, its files can continue to be accessed through other nodes, and the network will not be affected at all.https://ipfs.io/blog/25-pubsub/In addition to the storage tools released to application developers, IPFS also publishes an MQTT-like publish/subscribe event bus. Unlike MQTT, IPFS does not have a centralized Broker, but provides a completely decentralized and distributed Broker alternative. This means that subscribers who are interested in an event as a whole also act as a broker for other interested subscribers. Also, the built-in encryption security is an added bonus.
Now you can use the IPFS publish/subscribe scheme (Chris Matthieu), but users will quickly discover that IPFS requires nodes to opt in to store independent data. From then on, the structure, library and interested node "network" of large-scale projects based on IPFS will all run the same project application, thereby contributing value.One IPFS-based project is Computes.io. founderWrote a blog post about an IoT pub/sub example demonstrated last year using an Arduino (
). The word supercomputer might catch your eye, but the main takeaway from this example is that Computes fuse multiple computers into one, demonstrating brute-force password attacks.
IPFS allows us to connect a range of IoT devices and have them act as a shared file system, an event bus, or as Computes.io demonstrates, a distributed computing platform.
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Internet of Things Solution Based on Helium-Based Distributed Device Network
is another startup that caught our attention at Hologram. They're building a "decentralized network of devices," a term they've coined to describe their product. Helium's network combines physical blockchains, wireless technology, and open source software to create a distributed blockchain platform purpose-built for the Internet of Things.
When Helium first announced the "decentralized network of devices," they claimed on their website that "the Internet of Things has failed." Their reasoning is that the Internet of Things has not lived up to expectations because of the chaos created by the tangle of various protocols and proprietary technologies.
Helium has also developed a new cryptographic consensus mechanism for this network to provide incentives for the expansion and maintenance of the network. Instead of wasting resources on mining functions, Helium gateways provide a practical service to extend the network to a specific geographical area, which is verified by Helium's Proof of Coverage mechanism. As a result, gateways are rewarded with tokens for their efforts to contribute validation computing power to the underlying network.
IoT devices will use the WHIP protocol to securely connect to multiple local gateways within transmission range. After joining the network, the device sends encrypted data to all gateways.
The following is a step-by-step analysis of the data transmission mechanism of the Helium network.
IoT devices will use the WHIP protocol to securely connect to multiple local gateways within transmission range. After joining the network, the device sends encrypted data to all gateways.
Each gateway adds data to blocks, which are then added to Helium's global blockchain. The data object will contain routing information to forward sensor data.
The gateway sends the specified data to the specified route. After the router obtains the data transmission service, it will pay the gateway.
Since Helium is currently under development, the above description may be a bit messy. We hope to better describe this process in the future.
“We use the blockchain to reward contributors who deploy Helium gateways. This approach allows us to build a community-governed, decentralized network that provides secure, affordable, ubiquitous wireless coverage, connecting billions of devices to Connect to the Internet." - Helium
IOTAIoT solution based on IOTA entanglement
is another currently available technology. This project introduces the concept of entanglement (Tangle) network, which is different from the traditional blockchain network. Entanglement is a new form of distributed ledger technology designed with the Internet of Things in mind.
image descriptionUnlike blockchain, tangle is a tangle of user networks rather than miner nodes. The idea here is: for any device or user to initiate a transaction, it must also process the next two transactions. This scheme enables fast transactions with lower fees than any other scheme. IoT devices can quickly initiate small transactions for sensor data or functionality. This technology creates a whole new economic model for connected devices.An interesting proposition of IOTA is to protect the network from quantum computing attacks. This statement is difficult to verify, but it is worth thinking about.
In the future, the infrastructure of most cities will be managed based on sensor networks and distributed actuators. It is conceivable that cyber attacks involving spoofed identities or falsified data could lead to disastrous consequences. A secure IoT network based on quantum-resistant encryption can prevent such attacks during the node life cycle.
looking to the future
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looking to the future
It is still necessary to be skeptical of blockchain technology, but as the technology develops, it can do far more than create a currency.
Imagine an interesting future: devices are connected through micro-transactions initiated between independent gateways, and the entire network is distributed on a large number of private nodes; each device will maintain the system it depends on, and if a part of the system needs to be "offline" , the entire system can also fork or merge autonomously.
epilogue
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epilogue
Current IoT solutions rely on platforms that may become obsolete in a few years. Many of the projects I created myself stopped working because the services they depended on were down. The distributed projects mentioned in this article allow us to go beyond the limitations of a central manager. The new system is less likely to be compromised, and data is less likely to be lost.
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