Encrypt / Decrypt
Professional client-side AES, 3DES and DES encryption/decryption suite with NIST-authenticated AES-256-GCM defaults, PBKDF2 key derivation and structured JSON packaging.
What Does the Encrypt / Decrypt Tool Support?
This tool performs symmetric encryption and decryption — the same key (or a password, via key derivation) is used for both directions. It supports AES in several modes (GCM, CBC, CTR, and ECB), as well as legacy DES/3DES for compatibility, all running locally in your browser.
How to Use the Encrypt / Decrypt Tool
- Choose Encrypt or Decrypt, then select a cipher and mode.
- Provide a key directly, or enter a password and let PBKDF2 derive a key from it.
- Enter the plaintext (to encrypt) or ciphertext (to decrypt), along with an IV/nonce where the mode requires one.
- Review the result and copy it.
Technical Notes
- GCM is an authenticated mode — it detects tampering as well as providing confidentiality — and is generally the recommended choice when available.
- ECB mode encrypts identical blocks of plaintext into identical blocks of ciphertext, which can leak patterns in the data; it's included for compatibility, not recommended for sensitive data.
- Encryption protects data confidentiality only as well as the key or password behind it is protected — a weak password derived into a key is still a weak key, and losing the key means the data cannot be recovered.
Frequently Asked Questions
Which mode should I use — GCM, CBC, CTR, or ECB?+
Prefer GCM. It provides confidentiality plus built-in authentication, so it detects tampering. CBC and CTR provide confidentiality only and need a separate MAC. ECB leaks patterns because identical plaintext blocks produce identical ciphertext blocks; it is included for compatibility, not for protecting real data.
Does the IV or nonce need to be kept secret?+
No, but it must be unique for every encryption under the same key — for GCM and CTR, never reuse a nonce. The IV is not secret and is normally stored or sent alongside the ciphertext; losing it, however, makes decryption impossible.
Why are DES and 3DES included if they are outdated?+
Only for interoperability with legacy systems and old data. Their key strength and 64-bit block size are no longer considered adequate, so use AES — GCM by default — for anything new.