What is a public key hash

Encryption

Cryptographic procedures

Encryption makes information incomprehensible to outsiders. Only the initiated can encrypt or decrypt data with the help of so-called keys.

There are many different methods of encryption / decryption, which are also considered to be differently secure and are also used for different purposes.

  • symmetrical encryption method (secret key method):
    The same key is used for encryption and decryption. Only the sender and recipient of an encrypted message are allowed to know the key.
    Considered to be very efficient.
    Disadvantage: Replacing the key can be problematic.
    Known procedures: DES (Data Encryption Standard), IDEAS (International Data Encryption Algorithm), AES (Advanced Encryption Standard)
  • asymmetrical encryption method (public key method):
    Two different keys are used for encryption and decryption. The sender and recipient each have a private key, which must be kept secret in any case, and a public key.
    The encryption takes place with the public key of the recipient, the recipient can only decrypt the encrypted message with his private key.
    Disadvantage: The complex process is only suitable for encrypting small amounts of data.
  • hybrid encryption methods:
    Combination of symmetrical and asymmetrical encryption.
    A common session key is agreed and transmitted with asymmetric encryption. Further communication is encrypted symmetrically with the session key.
  • cryptographic hash procedures:
    This converts texts of any length to a character string with a fixed length, the so-called fingerprint. For the fingerprint, it should be practically impossible to determine the original text and to find a second text with the same fingerprint.
    Application: verification of passwords; Confirmation of the integrity (intactness) of e-mails, software or documents.
    Known methods: SHA-2, SHA-256, RIPEMD-160
    MD4, MD5, RIPEMD-128, SHA are now considered unsafe