Explain how symmetric key cryptography public key cryptograp

Explain how symmetric key cryptography, public key cryptography, hash functions, and digital signatures can be combined to provide email confidentiality, sender authentication, and message integrity.

Solution

Answer:-

Symmetric key cryptography :

Public key cryptography, or asymmetric cryptography, is any cryptographic system that uses pairs of keys: public keys which may be disseminated widely, and private keys which are known only to the owner.

This accomplishes two functions: authentication, which is when the public key is used to verify that a holder of the paired private key sent the message, and encryption, whereby only the holder of the paired private key can decrypt the message encrypted with the public key.

In a public key encryption system, any person can encrypt a message using the public key of the receiver, but such a message can be decrypted only with the receiver\'s private key.

Public key cryptography :

public key cryptography is often used to secure electronic communication over an open networked environment such as the Internet, without relying on a hidden or covert channel.

Hash functions :

a cryptographic hash function and then digitally sign the generated hash value therefore enforcing non-repudiation. Hashing is a much faster computation to complete as opposed to using an RSA-based digital signature algorithm alone. The sender would then sign the newly generated hash value and encrypt the original documents or files with the receiver\'s public key.

Digital signatures :

The digital signatures consists of a private signing key and a public verification key. The public key may be widely distributed, while the private key is known only to its proprietor. The keys are related mathematically, but the parameters are chosen so that calculating the private key from the public key is unfeasible.

The goal of a digital signature scheme is to ensure that the sender of the communication that is being sent is known to the receiver and that the sender of the message cannot repudiate a message that they sent.