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Hvad er tekstkryptering?

Tekstkryptering er processen med at konvertere læsbar tekst (klartekst) til et ulæseligt format (chiffer tekst) for at beskytte dens fortrolighed. Kun personer med den korrekte dekrypteringsnøgle kan læse den oprindelige besked.

Supported Algorithms:

Symmetric Encryption (AES):

• AES-GCM (Recommended): Provides authenticated encryption with associated data (AEAD). Most secure for general use.
• AES-CBC: Traditional block cipher mode. Requires padding.
• AES-CTR: Counter mode. Converts block cipher to stream cipher.

Asymmetric Encryption (RSA):

• RSA-OAEP: Uses public key for encryption. Limited to ~190 characters due to key size constraints. Use for encrypting small data or symmetric keys.

Output Format:

For AES algorithms: JSON with base64-encoded components

{"iv": "base64_encoded_iv", "data": "base64_encoded_ciphertext"}

For RSA: Base64-encoded ciphertext only (no IV needed)

base64_encoded_ciphertext

This format is compatible with most encryption/decryption tools and libraries.

Sådan bruges tekstkrypteringsværktøjet

1. Indtast den tekst, du vil kryptere, i inputfeltet.

2. Vælg krypteringsalgoritme (AES eller RSA).

3. Indtast en krypteringsnøgle eller klik på "Generer nøgle" for at oprette en.

4. Klik på "Krypter" for at sikre din tekst.

5. Kopier den krypterede tekst og del den sikkert.

6. Use the eye icon to show/hide your secret key for security.

Additional Tips:

• For AES: The secret key is auto-generated or you can provide your own (minimum 32 characters)
• For RSA: You need a public key in PEM format. Generate one using the Key Generator tool or OpenSSL
• RSA limitations: Can only encrypt short text (~190 characters). For longer texts, use AES algorithms
• Output encoding: Base64 is used for compatibility with other encryption tools and libraries

Security Notes

This tool uses the browser's native Web Crypto API for strong encryption. AES-GCM provides authenticated encryption with associated data (AEAD), making it the recommended choice for most applications. AES-CBC provides traditional block cipher encryption. Always keep your secret key secure and never share it publicly. The encrypted output includes both the initialization vector (IV) and encrypted data in JSON format.

Important Notes:

• All encryption happens locally in your browser using the Web Crypto API
• The IV (Initialization Vector) is automatically generated for each encryption and must be saved with the ciphertext
• For RSA encryption, you encrypt with a public key; decryption requires the corresponding private key
• Store your secret keys securely - if lost, encrypted data cannot be recovered
• Base64 encoding makes the output portable and compatible with most tools and programming languages

Krypter tekst sikkert med AES-256-GCM direkte i browseren. Ingen data sendes til servere.

Keywords: tekst-kryptering, AES-256, krypter besked, sikker kryptering