Identity verification and zero-knowledge: Imagining a private, secure future
Managing your identity used to be straightforward: Put your passport, birth certificate, and other personal documents in a safe place and share them face-to-face as needed. As the world moved online, we gained the convenience of verifying ourselves virtually, but also all of the challenges that come with managing our identity within a complex, fragmented digital framework.
Centralizing our data was meant to make things easier, but it made us an easier target. Data became concentrated in digital reservoirs, attracting hackers like bees to honey. We created a "messy" internet, with constant data breaches and third parties controlling our data, where personal data is regularly taken, sold, and abused.
But this narrative can change. We can reclaim control of our digital identities by leveraging blockchain and zero-knowledge technologies.
Challenging the status quo with zero-knowledge proofs
Zero-knowledge is a branch of cryptography that deals with proving the authenticity of information. It allows one party to verify to another party that they know private information without revealing it. We can achieve this by providing proof that the information satisfies certain conditions without disclosing any extra details.
In an identity context, the concept of verification is straightforward. It happens every time we hand over our identification so that a third party can confirm its details, such as checking that someone is over the age of 21 to buy alcohol in the United States. The tough part is ensuring that only the information we want to share gets shared. Every time someone looks at our ID to check our age, they can also see information like our date of birth, home address, and other personal information.
With zero-knowledge cryptography, we can disrupt the model of assuming trust and instead switch to "verify to trust". Now that trust is established through the verification of claims, individuals can prove that they are above a certain age, of a specific nationality, or any attestation relating to their identity without revealing sensitive information.
Complete anonymity may not always align with the practical goals of using digital identities. That's where selective disclosure using zero-knowledge comes into play. While the default setting prioritizes total privacy, privacy exists on a spectrum, and users should be able to share only necessary information.
How decentralization helps users truly own their identity
With zero-knowledge, users can flexibly present their digital identities for services online without fear of disclosing personal information. But what about ownership? Today, users don't truly control their identities: Companies and governments spend millions on collecting, storing, and securing centralized identity data.
The decentralized nature of blockchain allows identity data to be stored in a distributed ledger that is timestamped, immutable, and append-only. Instead of relying on a single central authority, the data is distributed across a network of computers. The distributed nature influences the availability and integrity of the data and drastically reduces the probability of fraudulent actors trying to change that data. Once data is appended to the ledger, it is cryptographically cost-prohibitive to alter.
In this ledger-based architecture, users store their identity information on a distributed ledger, eliminating the need for centralized data collection. Ownership and control over the data remain with the users, who secure it using cryptographic methods. This decentralized approach reduces data storage requirements, minimizes costs, and enhances security and privacy in managing identity information.
The decentralized nature of the ledger guarantees constant visibility and public access to records, but it's crucial that transactions related to identity aren't made public. Instead, they should remain private by default, which is where zero-knowledge cryptography comes in.
Aleo: The private-by-default blockchain
Applications built on a traditional blockchain are public by default and by design. They don’t provide the privacy required for a truly secure approach to identity verification and management.
Unlike traditional public-by-default blockchains, Aleo empowers users by granting them control over their information by implementing zero-knowledge cryptography. Aleo’s blockchain is publicly accessible, but the data on it is encrypted and controlled by each individual. State updates occur by generating and verifying zero-knowledge proofs.
As a result, users can maintain their privacy and authenticate without giving away unneeded details. They can decide the extent of personal information they want to share and the appropriate times and contexts to do so.
Meanwhile, verifying parties can reason and verify information without actually accessing or seeing it directly. This capability allows enterprises to benefit from a platform that inherently respects privacy, guarantees security via cryptography, and offers programmable flexibility through selective disclosure.
Aleo's design helps eliminate the risks associated with central data storage and the potential mishandling of sensitive information. Decentralizing identity data safeguards personal information from honeypots and the increasing threat of cyberattacks and data breaches.
Applications and use cases that require privacy and could benefit from ledger-based technology are no longer constrained by the limitations of transparent blockchains. The advantages of immutability and decentralized computing can be realized without sacrificing user privacy and data security.
We can do more than imagine a better future for identity verification. Let’s build it.
Our blog features the stories of developer and privacy advocates building a better internet with zero knowledge.
About Frank Chen
Frank leads consumer products at Aleo. Prior to Aleo, he was at Gitcoin, where he built the first instance of a quadratic funding mechanism with Vitalik Buterin and led 10+ rounds of quadratic funding for Ethereum public goods. Frank is an avid cook, writer, jiu-jitsu competitor and coach.
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