Zero-knowledge identity proof is a cryptographic technique which allows us to prove our digital identities without revealing private information about us while we interact and engage with various kinds of transactions online.

The zero-knowledge identity proof technique offers a way of verifying or providing proof of our identity whereby one party proves to know a particular piece of information without revealing other private information. Some examples of the zero-knowledge proof protocol include submitting proof of identity without disclosing your address or demonstrating that your bank account is sufficient for a particular transaction without revealing its balance.

In this article, we will focus on the use cases of zero-knowledge identity proof, benefits, and some statistics regarding the topic. In addition, we will present information on how zero-knowledge identity proof works to replace passwords. First, let’s look at what a zero-knowledge identity proof is.

## What is Zero Knowledge Identity Proof?

A zero-knowledge identity proof is a term used to refer to an authentication scheme where one party proves to the other to have a particular piece of knowledge that proves ownership of the identity. The prover verifies the required information without further disclosing any additional sensitive or personal information. This ensures that you maintain ownership of your sensitive private data.

Zero-knowledge proof (ZKP) alerts the verifier that the prover has the required information to confirm his identity. The method was introduced during the 80s by MIT researchers and is used to further enhance blockchain functionality. Zero knowledge identity proof is categorized into two areas: interactive and non-interactive.

The interactive version involves a sequence of tasks to be completed by the prover for verifying knowledge of some information. The method usually involves mathematical probability concepts to provide self-sovereign identity.

A non-interactive zero knowledge proof involves decentralized identity management that does not require any prover and verifier interaction.

The above two versions of zero knowledge proof involve the following three crucial prerequisites:

• Completeness; the verifier is convinced that the prover possesses the required information when the correct statement is submitted.

• Soundness; if the prover inputs the incorrect information or does not input any information at all, the verifier cannot be convinced as the statement can never be falsified.

• Zero-knowledge; the verifier cannot discover any other information concerning the prover; thus, personal data and sensitive data are kept anonymous.

## Pros and Cons of Zero** Knowledge Identity Proof**

**Pros**

• The technique is simple as it requires no complicated methods of encryption.

• It improves the users’ privacy by keeping vital information anonymous.

• It replaces the ineffective methods of authentication to strengthen information security.

• It improves scalability in the blockchain.

**Cons**

• It is potentially vulnerable to sophisticated technologies such as quantum computing.

• Has strict restrictions since the entire information gets lost when the transaction’s originator forgets some information.

• Zero-knowledge proof requires a significant computing power of around 2000 computations in one transaction.

• The technique is limited to mathematical equations and numerical answers; thus, using another method requires a translation.

**Zero Knowledge Proof Use Cases**

Zero-knowledge identity proof offers flexibility to users who wish to control some of their sensitive information. Thus, the technique has numerous uses when combined with blockchain. Some of the uses include:

**Messaging**

End-to-end encryption is pretty important for messaging as no one can access the encrypted message except the intended one. Messaging platforms enhance data security by requesting the users to verify identities.

As the zero knowledge proof technique advances, particular messaging platforms will find it easier to build end-to-end encryption without giving out any additional information. Using ZKP in messaging is among the popular emerging trends in blockchain.

**Authentication**

Zero-knowledge proof is used in facilitating the transmittance of sensitive data like authentication information. ZKP helps build a secure channel where users can fill in their personal information without revealing it, thus preventing data leakage to malicious parties.

**Storage Protection**

The storage utility field is another crucial area in which a ZKP can be deployed. Generally, a zero-knowledge proof has a protocol for safeguarding the storage unit and the information contained in the unit. Besides, it provides a seamless, secure experience by protecting the access channels.

**Blockchain Transactions**

Private blockchain transactions should never be revealed to a third party. However, the traditional methods of sending these transactions usually have numerous loopholes.

In this case, a ZKP comes in handy to close these loopholes. When integrated efficiently, the concept makes it challenging to hack or intercept blockchain transactions.

**Complex Documentation**

The fact that a zero-knowledge proof can encrypt massive data makes it ideal for controlling certain blocks that grant access to a particular user while refusing the same for another user. This way, complex documentation is protected from unauthorized users.

**File System Control**

Zero-knowledge proof is also implemented in file systems, where it adds security layers to different files, users, and logins. The security layers ensure that the stored data is difficult to hack or manipulate.

**Securing Sensitive Blockchain Information**

Lastly, the zero-knowledge proof is widely used in blockchain technology to revamp transactions. The various ZKP tools add high security to each block containing sensitive banking information. For this reason, the banks can only manipulate the required blocks when certain information is requested. The other blocks remain untouched and protected.

## Benefits of Zero-Knowledge Proof

• Zero-knowledge cryptography technique involves simple encryption.

• It is much secure since it requires no party to reveal any information.

• ZKPs significantly shortens blockchain transactions as users do not have to worry about the information’s storage.

## Zero-Knowledge Proof Scheme

The idea of zero-knowledge proof can be applied in more practical cryptography. For example, Tom wants Mary to prove that she knows the value of x in gx mod p = y, without revealing the actual value of x, which in this case, serves as a proof of identity, and its value can be revealed later to further distinguish Mary.

Let’s say Mary gives out a random number r to Tom to serve as x, then, C = gr mod p. After receiving C, Tom can request Mary to disclose the values of either r or (x + r) mod (p – 1). In either case, Mary will provide another random value but not the exact x value.

Similarly, Tom can verify any of the answers quickly. If the requested answer was r, then gr mod p should equal C. if the request was (x + r) mod (p – 1), then g (x + r) mod (p – 1) should equal the value of C.

In this case, (x + r) mod (p – 1) value can be viewed as an encryption for x mod (p – 1). When a random value is distributed equally between zero and (p – 1), the actual x value is not revealed.

## How Zero-Knowledge Identity Proof Replaces Passwords

**Completeness**

In the ZKP protocol, both parties must follow the set rules correctly for the statement to be true. Thus, the verifier finds no difficulty in verifying it without further assistance.

With password verification, even if the password is leaked, the verifier will not know if an unauthorized user is trying to access the system. The worst even happens in unlimited login sessions depending on the established frequency to allow multiple access from the same device without entering the password. In this case, anyone accessing a device can get entry to much of the sensitive data.

Thus, zero knowledge identity proof is ideal for use over password for authentication. Even if a third party accesses some information, the verifier will still detect them as they lack specific information, which is not the case with compromised passwords.

**Soundness**

If the required statement is incorrect, the verifier immediately identifies the prover as a pseudo. Thus, access will not be granted in this case since the prover has failed to provide the correct information. The verifier cannot be convinced, even if the prover insists that the provided information is the absolute truth.

With a “remember device” feature to automatically log in to some information after providing a password for the first time, anyone accessing the device can decide to view much of the information as the verifier already validated and entrusted the device. This cannot happen with zero-knowledge proof, as the prover has to provide specific information to convince the verifier.