Here are the most valuable questions about cross-chain operation, DAG and smart contract in the AMA event.
Cross-Chain Operation
At present, there are four kinds of mainstream cross-chain technology: notary technology, relay/sidechain technology, Hash-locking technology and distributed private key control technology. Which technology does PalletOne adopt? And what’s the characteristic of cross-chain technology of PalletOne?
Notary technology is a two-way cross-chain technology. Some projects adopting relay/sidechain technology support unidirectional cross-chain operation, such as Polkadot and cosmos. And some others support two-way cross-chain operation, including BTC Relay and Rootstock. As to Hash-locking technology, it’s more like a dependent relationship.
Distributed private key control is used in FUSION and WanChain. It distributes the control of private keys to a number of nodes throughout the public blockchain. Only when certain nodes are collected, can the full private key be restored and the account be unlocked. The private key can only be used once. Once recovered, it is mastered by one node, and the generation and fragmentation of the private key also require a trusted central authority.
From the aspect of trust model, notary scheme requires the confirmation of multiple notaries, which is also the most criticized characteristic. The notary is a third party, a privileged institution, and it is easy to become the weakest part in the trust system.
Both notary scheme and relay/sidechain model support cross-chain asset exchange and transfer, cross-chain contracts and asset mortgage. The functions supported by Hash-locking technology are relatively fewer, including cross-chain asset exchange and asset mortgage in most scenarios. But it doesn’t support cross-chain asset transfer and contracts.
Cosmos is more suitable for the private blockchain and consortium blockchain based on tendermint. For public chains such as Ethereum, an additional “peg zone on Tendermint” is required to execute the cross-chain operation, and the architecture is more bloated. While PalletOne uses a simple adaptor to achieve the cross-chain operation.
Cosmos realizes the exchange of information between different blockchains through the IBC protocol. When the hub verifies the message from the other chain, it must maintain the public key set of the corresponding verifier. In this term, when the Hub is executing cross-chain operation, it needs to manage the public keys on every blockchain. For PalletOne, it manages the multi-signature public keys by randomly selected Jurors.
Cosmos is based on POS consensus. While PalletOne is based on the multitasking Jury consensus based on DPoS, which has higher performance than Cosmos.
In general, PalletOne is more light-weighted compared to Cosmos. Besides, PalletOne is more than just cross-chain technology. ‘Pallet’ stands for cross-chain protocol and ‘One’ represents a high-performance ledger, on which the users can write smart contracts, issue new tokens, vote to manage the community and develop application for ecosystem. Only PalletOne can establish a complete blockchain ecosystem based on cross-chain technology.
PalletOne queries the transaction status of the original chain through a blockchain adapter deployed on the Jury node. The adapter can be connected to a local data interface or to a remote third-party query interface. PalletOne generates a multi-signature address through the Jury and the users during the cross-chain transaction, and then the user can transfer the original token to the multi-signature address to lock the original Token.
Locking doesn’t mean destruction. It’s maintained by several Jurors and users, and no single party can unlock the Token of the multi-signature address. The Jurors will lock the signature unless the conditions of the smart contract are met.
DAG
PalletOne uses DAG as the underlying storage infrastructure for its parallel writing capability. The difference between PalletOne DAG and traditional DAG such as IOTA and ByteBall lies in the fact that PalletOne DAG is not part of the consensus. The consensus is still achieved with DPOS algorithm under Mediator’s supervision. To illustrate the relationship between PalletOne DAG and Mediator, we need to understand the notion of “consensus partition”.
In the PalletOne network, at first there’s only one kind of Token — -PTN. Later, a developer issued A Token. Then, A Token will be independent from the accounting unit of PTN. If A Token becomes popular and valuable, then it can apply for independence and elect its own A Mediator. In this term, A Token will be totally independent from PTN chain and the unit will be generated by A Mediators.
Owing to the underlying structure DAG, PalletOne can run countless Tokens in parallel. Not a single popular application will affect the transactions of other Tokens. At the same time, PTN main chain will witness the generation of units in other chains and ensure the security of each Token through the independent Mediators.
From the perspective of a single Token, the bottom layer is a blockchain. From the perspective of multiple Tokens, it is a DAG structure, so there will not be double-spending and shadowchain problems.
Smart Contract
PalletOne prevents and resolves smart contract bugs in the following ways:
PalletOne provides SKD for each supported programming language. The developers can use their familiar programming languages such as Java and C++ to decrease mistakes.
PalletOne adopts UTXO Token model. Compared with the account model used by Ethereum or other projects, UTXO model can prevent most of the problems such as Token overflow and Token lock due to developers’ negligence.
Smart contract in PalletOne is upgradeable. If a user reports a loophole when using the smart contract, the developer can upgrade the original contract. It avoids the situation in Ethereum that even if the bug is found, the users can’t recover from the loss.
Regarding the centralization issue, PalletOne will transform from a centralized system to a decentralized system gradually. PalletOne has a powerful voting mechanism. Every time there’s any technical problem or PalletOne needs upgrading, the community will conduct a poll to make decision.
PalletOne smart contract cycle is divided into 4 stages: contract template deployment, contract deployment, contract invocation and contract termination.
1） At template deployment stage, the developer creates a new contract template and deploy it to PalletOne after validation.
2） At contract deployment stage, contract issuer sends template and contract initial parameters to Mediator. Then, the Mediator needs to convene a Jury. After that, Jury will create contract instance. After validation and execution, Jury will write the state data, contract ID and Juror list into distributed storage.
In the contract invocation stage, in other words the contract execution stage, the Jurors need execute the contracts independently, reach consensus within the Juror. And the Foreperson (head of Jurors) will output the results after validation.
If the contract execution is accomplished or the contract needs upgrading, the Jury need to be dismissed and some other conditions need to be met at contract termination stage.
For more information:
Official website: https://pallet.one/
E-mail: [email protected]
Telegram: https://t.me/PalletOneOfficialEN
Github: https://github.com/PalletOne
Twitter: https://twitter.com/PalletOne_org
Wechat official account: Pallet
