The other algorithm used is the Digital Signature Algorithm (DSA), created by the U.S. government. This was popular for some time, since RSA was patented. However, the RSA patent expired some time ago and DSA is not as common as it used to be. Hybrid systems use cryptography with a public key to exchange secret keys that are then used in a cryptography system with symmetrical keys. Most practical applications of cryptography use a combination of cryptographic functions to deploy a global system that provides the four desirable functions of secure communication (confidentiality, integrity, authentication and non-contestable). The public key infrastructure can be used to manage single-signature processes. Under a single identification policy, users can enter a unique password to access multiple accounts or applications. This simplifies things for the user and makes it easier for system administrators to manage user accounts and passwords. Suppliers and contractors saw the possibility of a large market, created businesses (or new projects in existing ones) and began to act for legal recognition and liability protection. A technology project by the American Bar Association published a comprehensive analysis of some of the predictable legal aspects of the operation of PKI (see ABA Digital Signature Guidelines) and soon thereafter, several U.S. states (Utah was first in 1995 in 1995) and other jurisdictions around the world began to legislate and legislate. Consumer groups asked questions about data protection, access and accountability issues, which were more considered in some jurisdictions than in others.
Cryptography with public keys is based on personal secrecy and not secrecy. Public key cryptography, as shown in Figure 11.10a, uses two different keys, a public key and a private key. It is essential that it is not possible to determine the private key from the public key. In general, the public key is small and the private key large. A pair of keys can be used several times. The number of access keys for N users is 2N. The algorithm is complex and more effective for short messages. Because of its computational efficiency compared to the symmetrical key, public key cryptography is generally not used for encryption and decryption, especially for mass data processing, for example. B in a VPN session or encryption device with a full hard drive.
However, public key cryptography is preferred for digital signatures (with original authentication) and for the secure distribution of volatile symmetrical keys. However – why do you need the configuration in the model – if the encryption/agreement key is defund by the selected asymmetric algorithm? A large number of cryptographic authentication schemes and protocols have been designed to provide authenticated key agreements to prevent man-in-the-middle and related attacks. These methods generally mathematically link the agreed key to other agreed data, such as the following: A widespread mechanism for repelling such attacks is the use of digitally signed keys that must be secured: if Bob`s key is signed by a trusted third party, guarantor of his identity, Alice can have great confidence in the fact that a signed key she receives is not an attempt to intercept Eve. If Alice and Bob have an infrastructure with public keys, they can digitally sign a Diffie Hellman key or exchange a Diffie Hellman public key.