如何Encrypt 具有 AES
加密 plaintext using the AES symmetric cipher, covering key sizes, modes, and IV generation.
问题
你需要加密数据 using AES 所以该 仅某人具有相同键 能够解密它.
前置条件
- Understanding 的 symmetric 加密
- Knowledge 的关键和 IVs
步骤
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1. Generate or obtain a key
AES supports 128, 192, or 256-bit keys. Generate a cryptographically random key of the chosen size. Never derive a key from a password by simple hashing; use a KDF like PBKDF2 or scrypt instead.
输入256-bit key输出32 random bytes -
2. Generate an IV or nonce
For modes like CBC and CTR, generate a random 16-byte IV for each encryption. The IV does not need to be secret but must be unique and unpredictable. Reusing an IV with the same key is catastrophic for security.
输入random IV输出16 random bytes -
3. Encrypt and store the IV with the ciphertext
Encrypt the plaintext using the key, IV, and chosen mode. Store the IV alongside the ciphertext (it is needed for decryption). Use an authenticated mode like GCM to get both confidentiality and integrity.
输入plaintext + key + IV输出ciphertext + IV + tag
预期结果
Ciphertext 该能够仅 是 decrypted 具有相同键 和 IV, 具有完整性保护如果 using GCM.
常见错误
- Reusing the same IV with the same key
- Generate a fresh random IV for every encryption. Never hardcode or reuse an IV.
- Using ECB mode
- ECB reveals patterns in the plaintext. Always use CBC, CTR, or preferably GCM for authenticated encryption.
排障指引
- If decryption produces garbage, verify the key, IV, and mode match on both sides.
- If using GCM, ensure the authentication tag is verified before using the decrypted data.
安全限制
- AES is only as secure as its key. Store keys in a secure key store, never in source code or config files.
- This tool runs locally. No key or plaintext is transmitted.