Produced by Odaily
Author |
Editor | Lu Xiaoming
Produced by Odaily
Author |
Editor | Lu XiaomingBinance announced that the next Launchpad project will be Harmony, and will announce the details of the token sale and the updated lottery arrangement on May 15.Harmony is a PoS-based sharding scheme that includes a beacon chain and multiple shard chains. The sharding scheme is generated through the process of random numbers, and in the random number generation scheme, the method of VRF (Verifiable Random Function) + VDF (Verifiable Delay Function) is selected. In terms of consensus algorithm, Harmony is based on the traditional PBFT algorithm. It has been improved and called FBFT Fast Byzantine Fault Tolerant Algorithm.
In terms of financing, co-founder Nick White said in an email in April,The company has raised $18 million. It is reported that the investment has received many important sources, including Silicon Valley's Consensus Capital Group, Australia's Bank Central Asia (BCA), Hong Kong's Lemniscap VC and Singapore's UniValues Associates.
Previously,
Odialy has done a detailed report on Harmony
, please refer to the following articles for specific project introduction:
"How to take the next step in the development of the public chain, "Harmony" and Ethereum 2.0 collision ideas"HarmonyTo this end, Ethereum has proposed version 2.0. Ethereum 2.0 will switch to Proof of Stake (POS algorithm) to achieve consensus. In addition, there is a two-layer design structure of beacon chain and sharding technology.
Public chains that Odaily recently contacted
It is similar to the development path of Ethereum 2.0.
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Currently, PoW algorithm and PoS algorithm are most used in the public chain, and there is also PBFT algorithm. Among them, PoW and PoS are based on the longest chain consensus, while PBFT is a practical Byzantine fault-tolerant algorithm. Through multiple rounds of message transmission between nodes, all nodes in the network can reach a consensus, thereby solving the Byzantine problem in the distributed system.
Lan Rongjian, co-founder of Harmony, believes that the advantages of the PBFT mechanism are energy saving, no need for proof of computing power, and no electricity consumption. However, the number of messages transmitted by traditional PBFT is large, so the number of supported nodes is limited under the premise of ensuring speed. According to reports, Harmony is improved on the basis of the PBFT algorithm, and it is called FBFT Fast Byzantine Fault Tolerant Algorithm.
image descriptionwhite paperOperation of FBFT consensus mechanism
The multi-signature mentioned here adopts the BLS (Boneh-Lynn-Shacham) signature scheme proposed by Stanford University professor DanBoneh et al. in 2001 and updated in 2018.
Introduction, the BLS signature scheme was inspired by ByzCoin, ByzCoin uses the Schnorr signature scheme for constant-size multi-signature aggregation, and message passing between verifiers. However, Schnorr multisigs require secret commitment rounds, resulting in two round trips for a single multisig. Harmony speeds up broadcasting by using BLS multi-signature improvements that only require one round trip.
The validators among the nodes are selected according to the Proof of Stake (PoS), and the leader is randomly generated according to the random number, and is responsible for compressing the received multiple signatures into one signature and broadcasting it. More, but on the other hand, in order to restrict the leader, there are corresponding punishment mechanisms. If the leader does not complete the work, it can be replaced according to the agreement. If there is a problem in the broadcast process, part of its rights and interests will also be deducted.
At this point, Lan Rongjian said that this is the fly in the ointment under this mechanism, because the TPS will be reduced when the leader is replaced.
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Beacon Chain and Shard Chain
Sharding expansion is the way most public chains currently choose. According to reports, Harmony is a PoS-based sharding scheme that includes a beacon chain and multiple shard chains.
It should be noted that the PoS here does not refer to the algorithm, but the mechanism of verifying the identity of the node through the form of mortgage tokens. It can be understood that Harmony is a public chain based on the PoS mechanism and adopts the BFT consensus algorithm. The PoS mechanism is reflected in the generation of verifiers we mentioned earlier. To become a Harmony verifier, a potential participant (or stakeholder) must hold a certain number of tokens, and the number of equity tokens will determine the votes allocated to the verifier The number of shares, each voting share corresponds to one vote in the BFT consensus.
In this way, on the one hand, the network cost of broadcasting block headers between shards is reduced; on the other hand, since the beacon chain and other shards all store the block header of a certain shard, it increases the difficulty of attacking a certain shard. Thereby improving safety.
In addition to enhancing the consistency and security of sharding transactions, the role of the beacon chain also exists as a secure random number generator. Lan Rongjian introduced that Harmony's sharding scheme is generated through the process of random numbers.
As for the random number generation scheme, Harmony chose the VRF (Verifiable Random Function) + VDF (Verifiable Delay Function) method. Lan Rongjian introduced that under the VRF random number generation method, the random number generation algorithm is written by the protocol layer. Okay, suppose there are 10 verifiers, each of them proposes a random number, and the random numbers of everyone are added together to generate the final random number. In this way, after the current 9 people report their random numbers, Then the 10th person can adjust his random number to influence the final result, resulting in an attack. However, after adding VDF, by delaying the calculation of random numbers and the instant finality of the PBFT mechanism, it can effectively prevent the intentional manipulation attack of the last announcer.
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In addition, the expansion of shards has to mention cross-shard transactions. If cross-shard transactions cannot be realized between shards, each shard will be independent of each other, which is meaningless.
Project Progress
Harmony's cross-shard transaction is divided into two steps. For example, send a certain asset from slice A to slice B. After slice A succeeds in verification, the corresponding amount of assets will be deducted, and a signature will be generated through consensus. The signature will be passed through the routing protocol between slices. Send it to chip B. After chip B verifies the signature, the asset will be sent to the target account through consensus.
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Project Progress
Harmony's programming language is EVM, compatible with Ethereum smart contracts, which reduces the migration cost of Ethereum developers. Considering that Harmony's development model coincides with Ethereum 2.0, it seems that it is eyeing DApps on Ethereum. According to Lan Rongjian, applications currently considered for access include decentralized exchanges, games, decentralized map applications (map information applications), etc. He said that high-frequency trading and relatively small transaction scenarios are more suitable.
In terms of team, the full-time team and the part-time team have a total of 16 people, including 9 technical people. CEO Xie Zhentao used to be a researcher at the headquarters of Microsoft Research, a senior software engineer at Google headquarters, and a chief engineer at Apple headquarters. He once founded Spotsetter, a company focused on mobile search, which was later acquired by Apple; Play Store Engineer.
secondary titleZilliqaandMultiVACIs it broken one by one or "sewing and mending"
At present, the public chain expansion solution is more recognized and accepted by the market is the sharding technology, Odaily previously reported
But the question is, is this kind of solution that seems to be broken and "sewn and repaired" really feasible?
I am Odaily reporter Wu Suixin (WeChat ID wsuixin12), please note your name, unit, title and reason when adding friends.
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