![Search icon](https://hackernoon.imgix.net/search-new.png?w=19&h=19)
Blockchain, without a doubt, revolutionized the world of finance and transactions by introducing secure digital currencies that are decentralized at the same time in the form of cryptocurrencies. Security and privacy remain the biggest issues to most because of the transparency and immutability offered by blockchain.
However, the solution lies in a term: zero-knowledge proofs, or ZKPs. These cryptographic protocols present a way of proving the statement's truth between two parties without revealing any information. In cryptocurrencies, ZKPs dramatically increase the privacy and security of transactions.
Probably the most common use case for ZKPs is to support use in anonymous transactions. Even with the identification and details of the transactions, cryptocurrencies employing ZKP still maintain their anonymity. The ZKPs greatly provide the ability to prove transactions without providing extra information and are perfect for privacy.
ZKP is a system that describes security in different kinds of cryptocurrency transactions. They help one verify that they are maintaining correct transaction records and managing open and closed ledgers, revealing key codes and data.
This type of defense limits the chance for jacking to be carried out on one's money in terms of double spending and changing the record of transactions.
Therefore, ZKPs make the record transparent while making it hard to rig the system in cryptocurrency systems. People can prove that the fundamental computation processes are appropriate to ensure that the system works all right. This confirmation makes sure that there exist no account details, transactions, cheating, and other evil associated with technology and society.
Thus, using zero-knowledge proofs in cryptocurrencies can help eliminate the major privacy and security problems while using digital currencies.
There are two types of ZKPs: Interactive and non-interactive.
Interactive Zero-Knowledge Proofs: In this, the communication switches between the prover and the verifier. The prover is the one who is convinced that he knows the secret sequence. The verifier will have a set of questions that the prover will need to answer convincingly. This technique is very secure and thus not appropriate in some blockchain applications because of the overhead in the communication costs.
Non-interactive zero-knowledge proofs: They are considered to be time-efficient since they allow the creation of a proof by the prover while also allowing it to be verified by a third party. This would make NIZKs really useful in solutions on a blockchain where the efficiency of a certain solution is of utmost importance.
Scalability, efficiency, and compatibility with the current infrastructure where they are implemented make a good rationale for implementation. A huge number of research and implementations of ZKPs within blockchain projects have presented their approaches and benefits.
Two of the most important protocols for ZKP are zk-SNARKs (Zero-Knowledge Succinct Non-Interactive Arguments of Knowledge) and zk-STARKs (Zero-Knowledge Scalable Transparent Arguments of Knowledge).
Zk-SNARKs: These find their way into general blockchain projects, for instance, Zcash. This category provides for very short proofs and makes it very efficient to use in blockchains. They come with a trusted setup—this means they have to generate the initial parameters securely.
Zk-STARKs: This is the second generation of zk-SNARKs. It doesn't require a trusted setup, therefore, it's more secure. It also enables scalability and transparency so that the creation of the proof can be verified by anyone. StarkWare is a leading company in blockchain scalability and the development of zk-STARK.
The first cryptocurrencies to be introduced, Bitcoins seem to have encountered challenges when it comes to privacy and scalability. Privacy and scalability will be addressed once ZKPs are integrated with Bitcoin.
While it has been admitted that Bitcoin transactions are pseudo-anonymous, what it really means is that the real-world identity of a person cannot be directly mapped to any transaction. Any information related to any kind of transaction is broadcast publicly on the blockchain.
This allows privacy improvement when using ZKPs; this means that transaction validations might even be possible without revealing all the information about the transactions. For instance, take the example of “Shielded Transactions of Zcash.“
Zcash is a digital money implementation designed upon the working of Bitcoin, extended with zk-SNARKs to permit completely shielded transactions. The sender and the receiver, along with the transacted money, are hidden from every observer and, thus, strongly covered by privacy. If the capability of zk-SNARK is implemented similarly, then it will definitely enhance the privacy of transactions in Bitcoin.
ZKPs can be used to ensure a more secure Bitcoin transaction as well, as integrity and validity should be guaranteed even in the presence of masked sensitive data. That comes in really handy, specifically where double-spending and other malicious activities need to be averted.
A good illustration of this is zkLedger, which is a blockchain protocol for audits. It is designed to preserve transaction confidentiality by using ZKPs and simultaneously ensuring data integrity.
The added advantage comes with the application of zkLedger principles to Bitcoin in that security is enhanced by the verification process that is carried out by the auditors without actually compromising the privacy of information.
There are many actual projects and real implementations that show the potential of ZKPs to support the case of security and privacy for blockchain.
StarkWare and DeversiFi
In this case, StarkWare is a technology designed with zk-STARKs, while DeversiFi is a decentralized exchange that is coming together to bring about scalable private transactions.
Filecoin with zk-SNARKs
This is in the sense that in most of their cases, Filecoin is a decentralized storage network; storage providers are in a position to provide proof of storing the data without necessarily revealing what the data is. This conclusively proves that ZKPs are very versatile in terms of security and privacy for different blockchain applications.
LayerEdge:
LayerEdge is aggregating zero-knowledge proofs (ZKPs) to reduce verification costs on the Bitcoin network by 90%. This advanced cryptography improves efficiency and strengthens LayerEdge's role as the leading verification layer on Bitcoin. Major industry players such as Nubit, Bittfinity, and BSquared are already using LayerEdge for their verification needs.
Deploying ZKPs is not trivial, although the plethora of benefits they bring is enormous. These are:
Computational Complexity: Highly intricate mathematical computations birth ZKPs, specifically zk-SNARKs and zk-STARKs. Work is ongoing to optimize such computations and make them efficient for general purposes.
Efficient Proof Generation: The next crucial necessity for the actual realization of ZKPs in blockchain protocols is the efficient generation of proofs. This research work is ongoing, with a steady increase in the time taken to prove it, without necessarily taking a toll on considerations of security.
This is not an easy problem; it must be carefully tested and designed to ensure it is compatible with current Blockchain protocols, such as Bitcoin. An area of critical ongoing research is bridging the gap between the traditional mechanisms of the blockchain and advanced cryptographic techniques.
Zero-knowledge proofs are an instantiation of another general class of utilities; they permit very strong and privacy-preserving transactions over the Bitcoin network, enabling a method that allows for transaction validation without revealing sensitive information.
The real-world implementations of such primitives are to show that ZKPs would be transformational in practice. There is no doubt that with ongoing research and development, ZKPs in Bitcoin and other blockchain protocols' integrations will pave the way for a new era of private and secure digital transactions.