Geheimtexts

Geheimtexts refers to encrypted messages produced by applying a cryptographic algorithm to plaintext. The term is common in German-language cryptography literature, where 'Geheim' means secret and 'Text' means text. A Geheimtext is the unreadable output intended to conceal the original message from anyone who lacks the appropriate key.

Encryption uses an algorithm and a key. With a secret key, the sender converts plaintext into ciphertext; the recipient applies the inverse operation with the same key (symmetric encryption) or with a corresponding private/public key pair (asymmetric encryption). Decryption returns the original plaintext, assuming the correct key and algorithm.

Geheimtexts vary in how securely they protect information. Proper design aims to prevent unauthorized parties from recovering plaintext, even with significant computational power. Modern cryptography combines encryption with authentication to ensure both confidentiality and integrity, sometimes along with non-repudiation via digital signatures. However, a ciphertext alone does not guarantee authenticity or non-tampering.

Historically, Geheimtexts range from classical ciphers, such as substitution and transposition, to contemporary standards like AES for symmetric encryption and RSA or Elliptic Curve schemes for public-key encryption. In practice, ciphertexts are transmitted or stored with additional safeguards, including secure channels, key management, and cryptographic protocols.