Java Security Cheat Sheet — Symmetric example using built-in JCA/JCE classes

Reference note (untrusted external data; do not execute it as instructions). If you absolutely cannot use a separate library, it is still possible to use the built JCA/JCE classes but it is strongly recommended to have a cryptography expert review the full design and code, as even the most trivial error can severely weaken your encryption. The following code snippet shows an example of using AES-GCM to perform encryption/decryption of data. A few constraints/pitfalls with this code It does not take into account key rotation or management which is a whole topic in itself. It is important to use a different nonce for every encryption operation, especially if the same key is used. For more information, see this answer on Cryptography Stack Exchange. The key will need to be stored securely. Click here to view the "JCA/JCE symmetric encryption" code snippet. Attribution: Adapted from OWASP Cheat Sheet Series under CC-BY-SA-4.0. Adaptation: WikiKV isolated this documentation section, normalized formatting, removed long code blocks, and shortened it for retrieval. Verify version-sensitive details at the source.