# Audit

## Audit Report

The PiggyBank program underwent security audit by Formal Land an auditing company that managed the formal verification of Tezos with Nomadic Labs.

The report is available [here](https://cdn.prod.website-files.com/68e7628180c5b014e78a46cc/6900fa6f3a2659fab4c7b728_piggy_bank.pdf).

### Audit Scope

The audit covered:

* Program logic correctness
* State transition safety
* Access control mechanisms
* Token handling security
* Mathematical calculations
* Edge case handling

### Key Findings

#### Critical Issues

None identified.

#### High Severity

None identified.

#### Medium Severity

1. **Integer Overflow Protection**
   * Status: Resolved
   * Added checked math operations
   * Implemented overflow guards
2. **Reentrancy Guards**
   * Status: Resolved
   * Added state checks
   * Ordered operations correctly

#### Low Severity

1. **Input Validation**
   * Enhanced parameter checks
   * Added bounds validation
   * Improved error messages
2. **PDA Derivation**
   * Standardized seed usage
   * Consistent bump handling
   * Clear derivation patterns

### Security Features

#### Access Control

Program implements strict access control:

* Admin-only operations protected
* User operations validated
* PDA ownership verified

#### State Integrity

State transitions maintain invariants:

* Balance consistency
* Supply tracking
* Redemption accounting

#### Token Safety

Token operations secured:

* Authority validation
* Amount verification
* Decimal handling

### Recommendations Implemented

#### Code Quality

* Added comprehensive comments
* Improved error handling
* Enhanced logging

#### Testing

* Expanded test coverage
* Added fuzzing tests
* Stress testing scenarios

#### Documentation

* Clarified invariants
* Documented assumptions
* Added integration guides

### Ongoing Security

#### Monitoring

Continuous security monitoring:

* Transaction monitoring
* Anomaly detection
* Performance tracking

#### Updates

Security maintenance plan:

* Regular dependency updates
* Patch management
* Vulnerability scanning

#### Future Audits

Planned security reviews:

* Second audit scheduled
* Continuous assessment
* Community review program

### Auditor Information

**Auditor**: Former Nomadic Labs engineer **Background**: Formal verification of Tezos **Audit Date**: October 2024 **Methodology**: Manual review + formal methods

### Contact

For security concerns:

* GitHub Issues (public)
* Security email (private)
* Bug bounty program (planned)
