Encryption

Choose AES-GCM (128 / 192 / 256-bit), AES-CTR (256), or AES-CBC (256, PKCS#7). PBKDF2-SHA256 with 200 000 iterations derives the key from your passphrase; each message uses a random salt and IV.

Output is Base64 with a TW2 header so the tool knows which algorithm was used; older blobs (salt+IV+ciphertext, GCM-256 only) still decrypt. Use the swap control to exchange input and output panes.