Mina

We express our gratitude to the Mina team for the collaborative engagement that enabled the execution of this dApp Security Assessment.

Mina Credentials is a library that enables privacy-preserving credential verification where users can prove certain attributes about themselves without revealing the underlying data.

The library is intended to help with importing real-world credentials into the Mina ecosystem: For example, to "import" your passport, you have to verify the passport authority's signature on your passport data. The signature relies one of several hashing and signature schemes such as ECDSA, RSA and SHA2-256, SHA2-384, SHA2-512. Also, the signature will be over a dynamic-length string.

This creates a modular, extensible system where various forms of identity and authorization can be represented while preserving privacy through zero-knowledge cryptography.

The system users should acknowledge all the risks summed up in the risks section of the report

Document Quality

• The project includes a thorough RFC and technical specification that clearly define the credential formats, protocols, and security considerations.

• Documentation is distributed across multiple files with some incomplete sections, including a design document that ends mid-sentence.

• While the technical aspects are well-documented, the project lacks user-oriented guides and integration examples that would facilitate adoption.

Code Quality

• The codebase demonstrates strong TypeScript implementation with consistent naming conventions and comprehensive type definitions throughout.

• Core cryptographic functionality is implemented with careful attention to detail, particularly in the zero-knowledge proof systems and context binding mechanisms.

• Some complex components could benefit from additional inline documentation and more explicit error handling to improve maintainability.

Architecture Quality

• The architecture effectively separates credential types (simple vs. recursive) and establishes clear protocols for issuance, presentation, and verification.

• The system is designed with composability in mind, allowing for flexible credential formats while maintaining consistent security properties.

• The credential presentation model successfully balances privacy needs with practical verification requirements, though the complexity might present adoption challenges.

Test coverage

Code coverage of the project is 93.52% statement coverage and 81.73% function coverage

• The project includes both unit and integration tests covering core functionality including serialization/deserialization, credential operations, validation, and the presentation protocol.

• Tests are well-structured using Node.js's test framework with clear assertions and a mix of positive and negative test cases across the dynamic data structures and cryptographic operations.

• While test coverage appears thorough for the most critical components, there are no explicit coverage metrics, and some areas like stress testing, performance benchmarks and edge cases.

The Mina Credentials system is a zero-knowledge credential framework built using o1js to implement privacy-preserving credential verification using recursive SNARKs to enable selective disclosure of attributes.

Core Components

1. Credential Types

2. • Simple Credentials: Based on native Mina signatures over attribute sets

   • Recursive Credentials: Leveraging Kimchi proofs to support arbitrary verification logic

3. Cryptographic Primitives

4. • Dynamic hashing with Poseidon for credential integrity

   • Context binding using domain-separated hash constructions

   • SHA-2 implementations for compatibility with existing standards

5. Protocol Flow

6. • Credential issuance generating cryptographic attestations with issuer signatures

   • Selective disclosure presentations via zero-knowledge proofs

   • Context-bound verification preventing credential replay attacks

7. Data Structures

8. • DynamicArray: Variable-length arrays with ZK-efficient operations

   • DynamicBytes: Specialized container for byte sequences

   • DynamicString: UTF-8 string representation optimized for ZK circuits

   • DynamicRecord: Key-value store with dynamic field access

   • StaticArray: Fixed-length arrays for ZK-friendly operations

   • DynamicSHA2: Implementation of SHA-2 hash function for dynamic data

   • DynamicHash: Hashing of dynamic data types using Poseidon

9. Security Model

10. • Owner binding via public key authentication

    • Issuer identification through commitment schemes

    • Non-malleability guarantees through signature verification

    • Simulation-extractable presentation protocol

The system achieves composable privacy by separating credential issuance from presentation, allowing third-party issuers while maintaining user control over selective disclosure through a unified presentation protocol.

The scope of the project includes the following components from the provided repository:

Components in scope

• src/ excluding the test files *.test.ts

• spec/ for reference

• apps/extension/

Assets in Scope