How does the Zecrey Protocol keep account information private?

There are two main ways to save transactions in the blockchain world: the Account model and the UTXO model. Both of these methods are very popular in today’s world.

The Account model is similar to the concept of the real world, where the account name and address can be used as a blockchain account. The account’s balance is then recorded in the distributed ledger.

For an example, let’s say that Alice has 10 tokens in her account and Bob has 20 tokens in his account. Through a transaction, Alice’s token balance will decrease by 5 tokens.

The account balance is computed dependent on the transactions that happened on the blockchain. This dependency increases the risk that adversaries could obtain account details through unauthorized transactions.

Strictly keeping account details private is very important. However, conventional encryption schemes can’t work on encrypted data without first decrypting it.

Homomorphism is a type of encryption that retains the same algebraic structure as its plaintext counterpart.

Although many public-key encryption schemes support partial homomorphism, they only support addition and multiplication operations on the encrypted text.

Homomorphic encryption can be divided into three main categories: partial homomorphism, fully homomorphic encryption, and additive homomorphism.

Partial homomorphic encryption (SHE) supports only a limited number of operations, such as addition or multiplication.

Due to its limited functionality, PHE is too complex to be adopted in real-world applications. To avoid this issue, Zecrey has created twisted ElGamal, a fully homomorphic encryption scheme.

Unlike the standard ElGamal, it is zero-knowledge-friendly. Also, its second part is not linked to the same commitment key.

With twisted ElGamal, zero-knowledge proofs that are based on the form Pedersen commitment can be easily aggregated.

Moreover, since twisted ElGamal is more efficient than the most widely used encryption scheme, it has been considered as the most effective privacy protection method.

Zecrey Protocol was launched in February 2021, by a few PhDs with backgrounds in cryptography. Its first major milestone is the launch of its test network in July.

The Zecrey Account model is an alternative to the UTXO model due to its flexibility and programmability. It can be easily used by a wider variety of projects.