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Text Encryption

Securely encrypt and decrypt text with a password using AES

テキスト暗号化復号

パスワードでテキストを安全にAES暗号化・復号

About Text Encryption

The Text Encryption tool is a browser-based utility that securely encrypts and decrypts text using AES encryption via the Web Crypto API. All processing happens entirely in your browser, and no data is ever sent to a server. Your password and text never leave your device, making it safe for encrypting sensitive information.

The encryption mechanism works as follows: your password is processed through PBKDF2 (100,000 iterations with SHA-256 hashing) to derive a 256-bit encryption key. This high iteration count of 100,000 significantly strengthens resistance against brute-force attacks. The text is then encrypted using either AES-GCM-256 or AES-CBC-256, combined with a random salt and initialization vector (IV), and output in Base64 format for easy sharing.

Regarding algorithm selection, AES-GCM-256 is recommended as it provides authenticated encryption with tamper detection. AES-CBC-256 is available for compatibility when needed but does not provide the same level of robustness. In the Decrypt tab, you can restore the original text by entering the encrypted Base64 text and the correct password.

How to use Text Encryption

  1. Enter text in the Encrypt tab and set a secure password, then click Encrypt (we recommend 8+ characters with mixed case, numbers, and symbols for sensitive data)
  2. Copy the encrypted Base64 text and share it securely via email, chat, or cloud storage (encrypted data is safe to transmit publicly)
  3. In the Decrypt tab, enter the encrypted text and the same password, then click Decrypt to restore the original text
  4. Choose between AES-GCM-256 (recommended) or AES-CBC-256 algorithms (use GCM for most purposes)

Benefits of Text Encryption

  • Fully browser-based processing means your text and password never leave your device (guaranteed privacy)
  • Strong key derivation with PBKDF2 (100,000 iterations) provides high resistance against password cracking (more than 10x industry standard iterations)
  • AES-GCM-256 authenticated encryption detects any tampering with encrypted data (recipients can verify data integrity)
  • Base64 output can be shared directly via email or chat, and recipients can decrypt with the same password (platform-agnostic)
  • AES-CBC-256 option available for legacy system compatibility when needed

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