In real life, only our government and banks have the way to know our personal property, but it is very different in a digital currency world like Bitcoin. Because the blockchain is an open and unchangeable ledger, when you transfer coins from one address to another, anyone can find your transaction history through your transfer address. Bitcoin users can have many bitcoin addresses, and although there is no inevitable connection between these addresses and their true identities, more and more studies show that by means of social engineering and statistics, the address of the bitcoin wallet and a certain identity of the user (such as the user's IP address or the user's real identity information) can be linked, and the context of the user's funds and the network of relationships will be visible all the public.


In order to solve this privacy problem, some solutions have emerged in the digital currency field. such as Dash has a certain degree of anonymity in its coins by a centralized coin blender, and Monero has improved its transaction structure by using ring signature. A simple description of a ring signature is that if 10 people send a transaction, only one person's signature is signed into the transaction, and because only one signature is used, everyone is not sure who it is.


In the field of anonymity, the privacy protection scheme based on zero-knowledge proofs is recognized as the most sophisticated technical means, making it highly sought after by the technical experts. The zero-knowledge proofs technology ZK-sNARKs used by its representative currency Zcash achieves complete hiding of transaction records and amounts. This technique can simply assume that all coins (non-transparent transactions) are taken out of a large pool of decentralized mixed coins, which realizes the interchangeability of Zcash coins(ZEC) - there is no difference between any two coins.


Zcash was founded by top cryptographers and security experts and has attracted much attention before it was born. On October 28, 2016, when its creation block was born, the ZEC coin price once reached 3,300 BTC and investors' frantic hype was shocking. For a long time, Zcash has been the top ten in the digital currency market. It is recognized as the leader of anonymous currency. However, with the further development of technology in the digital currency field, ZEC coin prices have gone from bad to worse its ranking has also been falling, surpassing Monero and Dash one after another and now only ranks around 20, why Zcash will fall from the altar of privacy coins? Let us analyze the reasons.


First, not all ZEC transactions are defaulted to privacy, while private transactions can only be initiated from a special "Z address" and require high transaction costs. One possible reason for this artificial limitation is that the zero-knowledge proofs technology used by Zcash uses digital circuits to encode its proofs when it initiates a private transaction. The speed of this step is very slow, and it may take hundreds of seconds on ordinary laptops, which greatly affects the user's experience.


In addition, Zcash's entire code base was a branch modified on the basis of Bitcoin version 0.11.2, retaining the original model of bitcoin, which means it can only support some simple transactions, simply a preset privacy Bitcoin network for privacy protection mechanisms. In this way, the programmability of digital currency cannot be realized. If developers build business applications using privacy protection technologies, such as enterprise supply chain management, financial transactions, social networks or online shopping systems using block chain systems, it is impossible to use Zcash, which requires the blockchain system to support smart contracts so that developers can incode these business logics in the language smart contracts.


In response to these problems with Zcash, many R&D teams are trying to make further improvements in the in the area of blockchain. However, due to the academic and engineering complexity in the field of the zero-knowledge proofs, most teams have made slow progress and have not developed a system that can actually run online.


Recently, a project called SERO was successfully launched and solved the above problems of Zcash. SERO is the meaning of Super Zero. It is the world's first blockchain-based platform that implements privacy protection based on zero-knowledge proofs technology and supports Turing's complete smart contract. In the aspect of zero-knowledge proofs system, the SERO team built the Super-ZK zero-knowledge proofs encryption system based on zk-SNARKs. At present, the Super-ZK system is more than 20 times faster than Z cash's current system in the biggest bottleneck of the popularization and application of zero-knowledge proofs, which will further improve the prospect of zero-knowledge proofs system's practicality.


At the same time, the SERO team has worked hard for a long time to make Turing's complete smart contract really run on the anonymous blockchain system, g greatly expanding the application field of the blockchain system in the industry. From now on, the issuing rights of secure anonymous digital assets are no longer exclusive to a few geeks that have deep knowledge of cryptography. Ordinary system developers, as long as they have the business needs to issue anonymous digital assets, can issue their own anonymous digital assets on the SERO chain to establish their own privacy ecosystem. In addition, because of the Turing's completeness of smart contracts on the current version of the SERO chain, it is also supported to issue and exchange privacy tickets of complex data structures. Anonymous tickets support a rich data structure, greatly expanding the scope of application of privacy smart contracts, allowing blockchain application developers to put business-related data securely on the chain without worrying about the privacy disclosure of related data.


It is believed that with the further development of systems such as SERO, they will promote the further popularization of privacy blockchain technology. As a pioneer of privacy currency based on zero-knowledge proofs, Zcash demonstrates the engineering feasibility of this sophisticated security encryption technology, and the zero-knowledges privacy application development ecosystem pioneered by SERO will bring more prosperous development pattern in this field.