Blockchain can solve the problem of mutual trust in transactions.

Smart contracts solve the problem of mutual trust in transactions. Since the birth of Bitcoin, blockchain technology has been developing continuously. In 20 14, Ethereum further developed the intelligent contract technology with many new functions, and the intelligent contract was wound in digital form. "Once the information recorded in the blockchain is generated, it will be permanently recorded and cannot be tampered with", which can solve the trust problem of "unfamiliar trust".

Ulord has the property of smart contract and introduces the design concept of gas, but unlike Ethernet gas, every operation consumes gas. Compared with the gas concept of Ethernet, Ulord adopts a more simplified and abstract method. The resources and sites published by users on Ulord consume the resources on Ulord network, so users need to bind a certain number of UlordToken when publishing resources or sites. With the increase of block height, UlordToken will be gradually consumed, and users need to fill in a new UlordToken at the address corresponding to the consuming site to ensure the ownership of the domain name. At the same time, through the side chain technology, it can be compatible with Ethernet virtual machines, issue smart contracts, and allow users to issue their own tokens. There is a certain proportion of exchange relationship between Token and UlordToken. Ulord allows users to customize their own site services and operate their own sites by issuing their own tokens.

Zk-SNARK technology to protect transaction privacy Ulord will adopt the most mainstream privacy protection zk-SNARK technology to protect transaction privacy. In the view of Ulod Blockchain, creating an effective transaction includes the following three things:

1.？ Ensure that the currency in this address has not been used in previous transactions;

2.？ The sender proves that he is the "holder" of the currency by means of authorized signature;

3.？ The input of a transaction is equal to its output.

Prove that the work that has not been spent before the money is done by the account book itself, and the sender does not need to do any work. The sender only needs to prove that he is the holder of these currencies, and wants to send these currencies by electronic signature with the private key corresponding to the address. In order to verify this signature, the sender's address must be public. Accordingly, the receiving party must also disclose the receiving address to complete the transaction process. In the use of Ulord, it is very simple to verify whether the input and output of the transaction are equal, because the number of transmissions is completely revealed.

Using zero-knowledge proof (specifically zk-SNARKs) to verify the above three elements can protect the privacy of users from being leaked, that is, the information of the sender, payee and transfer amount will not be disclosed. Every successful transaction is accompanied by zk-SNARK, which proves that the invested assets exist and have not been spent before. The person who created the transaction authorized to spend the transaction, and the quantity and type of input are equal to the quantity and type of output. The information required for expenditure output (that is, creating a new zk-SNARK) is attached to the transaction, encrypted with the payee's public key, and used only by the payee.