State Secret sm4 encryption/decryption

1. SM4 is a block cipher algorithm developed by the State Cryptography Administration of China. It serves as the industry standard for commercial cryptography in China, and its official designation is "GM/T 0002-2012 SM4 Block Cipher Algorithm."

2. The SM4 algorithm is a symmetric-key encryption algorithm with a key length of 128 bits and a block size of 128 bits.

3. The design of the SM4 algorithm adopts an algorithmic structure similar to that of the international Advanced Encryption Standard (AES), though the specific algorithmic details differ.

4. The SM4 algorithm consists of 32 rounds of nonlinear iterative processing, with each round using a round key generated from the master key via a key expansion algorithm.

5. The SM4 algorithm has been widely adopted in fields such as finance, government affairs, and e-commerce, and is a crucial component of China’s information security framework.

6. All data processed by this tool is handled locally within your browser and will not be uploaded to any web servers. Please use it with confidence!

Instructions:

1. Key/IV Data Format: Please select the data format corresponding to your key/IV; the tool will automatically convert it to the required HEX format.

2. If the key/IV data format is text, select "Text" under "Key/IV Data Format"; if it is Base64, select "Base64" under "Key/IV Data Format."

3. Under "Encrypted Result Data Format," select the output format for the encrypted result; HEX format is recommended.

4. The type selected for "Decrypted Content Data Format" must match the format of the content entered in "Decrypted Content." For example, if the decrypted content is Base64, select Base64 for "Decrypted Content Data Format."

5. When the "Encryption Mode" is set to "CBC," you must enter an IV value. Please pay attention to the required input format.