Hash Tool

What is Hash Algorithm?

A hash algorithm is a mathematical function that converts input data of arbitrary length into a fixed-length output. It has characteristics such as one-way (irreversible), deterministic (same input produces same output), and avalanche effect (small input changes cause large output changes).

Supported Algorithms

MD5

Output Length: 128 bits (32 hex characters)

Security: Compromised, not recommended for security scenarios

Use Cases: File verification, data deduplication (non-security scenarios)

SHA-1

Output Length: 160 bits (40 hex characters)

Security: Compromised, not recommended for new projects

Use Cases: Git version control, legacy system compatibility

SHA-224

Output Length: 224 bits (56 hex characters)

Security: Good security, but less commonly used

Use Cases: Specific protocol requirements, embedded systems

SHA-256

Output Length: 256 bits (64 hex characters)

Security: Currently secure, widely used

Use Cases: Password storage, digital signatures, blockchain

SHA-384

Output Length: 384 bits (96 hex characters)

Security: High security, good performance

Use Cases: High-security scenarios, SSL/TLS

SHA-512

Output Length: 512 bits (128 hex characters)

Security: Highest security, suitable for high-requirement scenarios

Use Cases: High-security password storage, digital certificates

SHA-3

Output Length: 256 bits (64 hex characters)

Security: Latest standard, quantum-resistant

Use Cases: Future security standards, advanced cryptographic applications

RIPEMD-160

Output Length: 160 bits (40 hex characters)

Security: Good security, but less commonly used

Use Cases: Bitcoin address generation, specific cryptographic applications

SM3

Output Length: 256 bits (64 hex characters)

Security: Chinese national cryptographic algorithm, compliant with GM standards

Use Cases: GM applications, government systems, financial systems

Common Use Cases

Data Integrity Verification

Verify whether data has been tampered with during transmission or storage

Password Storage

Securely store user passwords (requires salt)

Digital Signature

Verify data source and integrity

File Verification

Verify the integrity and authenticity of downloaded files

Blockchain

Proof of work, transaction verification, etc.

Cache Keys

Generate unique cache keys

Security Considerations

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Collision Resistance

MD5 and SHA-1 have been proven to have collision vulnerabilities and should not be used in security-sensitive scenarios

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Salt Usage

Random salt should be used when storing passwords to prevent rainbow table attacks

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Algorithm Choice

New projects are recommended to use SHA-256 or stronger algorithms

Frequently Asked Questions

Can hash algorithms be reversed?
No. Hash algorithms are one-way functions and cannot reverse the original data from the hash value. However, brute force attacks or rainbow table attacks can be used to try to find the original data.
Can different inputs produce the same hash value?
Theoretically possible, this is called a hash collision. However, in cryptographically secure hash algorithms, finding collisions is computationally infeasible.
Does file size affect hash calculation time?
Yes. The larger the file, the longer it takes to calculate the hash. However, the length of the hash value does not change due to file size.