Analysis of Move Language Security: A Game Changer in the Smart Contracts Field

As a new generation smart contracts language, Move prioritizes security from its initial design. This article will explore the security of the Move language from three aspects: language features, operating mechanisms, and verification tools.

1. Security features of the Move language

The Move language achieves a secure programming model by sacrificing some flexibility features and adopting concepts such as generics, global storage, and resources. Its main security features include:

• Modular design, each module consists of structural types and process definitions
• Resource type structure, can be stored in global key-value storage
• Global storage mechanism that allows modules to have exclusive access to their declared resources.
• Invariant reduction, used for static checking of the conservation of system states.
• Bytecode verifier, enforces type safety and linear logic

The bytecode verifier mainly performs the following checks:

1. Structure legality check
2. Semantic detection of process logic
3. Error checking during connection

Through these mechanisms, Move can ensure a high level of code security at compile time.

2. The Operating Mechanism of Move

The Move program runs in the virtual machine and has the following security features:

• Cannot directly access system memory
• Execute on the stack, global storage is divided into memory and global variables.
• Execute bytecode instructions using a stack-based interpreter
• Resource value can only be destructively moved
• The state consists of the call stack, memory, global variables, and operation array.
• The calling process has no circular dependencies to avoid reentrancy issues.
• Data storage and call stack separation

This design has greatly improved both security and execution efficiency.

3. Move Prover

Move Prover is a reasoning-based formal verification tool that can:

• Use formal language to describe program behavior
• Verify program correctness through reasoning algorithms
• Adopted deductive verification algorithm
• Describe verification specifications using the Move specification language
• Generate verification report, pointing out potential issues

Move Prover is a very useful automated auditing assistant tool that can help developers enhance the security of smart contracts.

Summary

The Move language has comprehensively considered security in terms of language features, virtual machine execution, and security tools. It can effectively avoid common EVM vulnerabilities such as reentrancy and overflow. However, security issues in areas such as authentication and logic design still need attention.

Although Move has many advantages in terms of security, it is still recommended that developers use third-party security audit services and have professional security teams write and verify protocol code to further ensure the security of smart contracts.