CryptographyDEV

Text encoding, cryptographic hashing, symmetric & asymmetric encryption.

About Cryptography Toolkit

Overview

This toolkit integrates 20+ industry-standard cryptographic algorithms, covering four major categories: text encoding, cryptographic hashing, symmetric encryption, and asymmetric encryption.

100% Client-Side Processing—
Zero Network Transmission:

All cryptographic operations are performed locally on your device. All sensitive data (plaintext, ciphertext, keys, etc.) never leaves your device, ensuring complete privacy and security.

Select a specific algorithm to view detailed technical documentation, including algorithm history, security analysis, recommended parameters, and professional guidance.

SM4 (国密)

SM4 (formerly SMS4) is a block cipher standard (GM/T 0002-2012) published by China's State Cryptography Administration in 2006, using 128-bit keys and 128-bit blocks. It's a core algorithm in China's commercial cryptography system.

Key Features: Uses a 32-round unbalanced Feistel network with S-box nonlinear transformation. Design draws from AES and DES, balancing security and performance.

Modes of Operation:
CBC Mode: Requires IV (Initialization Vector), provides good security. IV must be randomly generated and never reused.
ECB Mode: No IV required, but poor security—not recommended for production.

Use Cases: Primarily for Chinese cryptography compliance—government systems, financial institutions, telecom operators, and critical infrastructure. China's Cryptography Law requires domestic algorithms for systems involving national security and public welfare.

Recommendation: Use SM4 if your project requires national cryptography compliance or deployment in Chinese government/financial sectors. Use SM4-CBC mode. For international projects without compliance requirements, AES is more universal.