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.

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)

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