SHA-1 File Hash Generator

What is SHA-1?

SHA-1 is a cryptographic hash function that produces a fixed-size hash value from variable-length input data. It's part of the SHA-2 family designed by the NSA and published in 2001. SHA-1 produces a 1-bit hash value and is widely used in security applications and protocols. This tool allows you to upload files and calculate their SHA-1 hash for verification and integrity checking.

How to Use SHA-1

1. Click "Select File" or drag and drop your file into the upload area. 2. The SHA-1 hash will be calculated automatically. 3. Copy the resulting hash value for verification or storage. All processing happens locally in your browser - no files are uploaded to any server.

When to Use SHA-1

Use SHA-1 when you need secure cryptographic hashing for certificates, blockchain applications, password storage, or data integrity verification in production systems.

How SHA-1 Works

SHA-1 uses a Merkle–Damgård construction with multiple rounds of bit operations including rotations, modular additions, and logical functions. Each message block goes through compression functions that mix the input thoroughly. The file is read in chunks and processed incrementally to handle large files efficiently without loading the entire file into memory.

Common Use Cases

• SSL/TLS certificates
• Blockchain technology
• Digital signatures
• Password hashing
• HMAC authentication
• File integrity checks