Cryptography is the practice of securing communication through mathematical techniques, such as encryption, decryption, and key exchange.
Asymmetric cryptography, also known as public-key cryptography, uses a pair of keys: a public key and a private key. Some of the commonly used algorithms for asymmetric cryptography include RSA, Diffie-Hellman, and Elliptic Curve Cryptography (ECC).
A typical use case for asymmetric cryptography is secure communication over an insecure network, such as the internet. For example, when a user wants to send sensitive information to a server, they can encrypt the data using the server's public key. Only the server, which holds the corresponding private key, can decrypt the data.
Another use case for asymmetric cryptography is digital signatures. Digital signatures can be used to ensure the authenticity and integrity of data. For example, a digital signature can be added to a software package to ensure that it has not been tampered with.
One case study of asymmetric cryptography is the use of SSL/TLS for secure web communication. SSL/TLS uses asymmetric cryptography to establish a secure channel between the client and the server. The client and server exchange public keys and use them to negotiate a shared secret key, which is used for symmetric encryption of the data exchanged over the secure channel. This enables secure communication over the internet, such as online banking transactions, e-commerce, and secure email communication.
Symmetric cryptography uses a single secret key to encrypt and decrypt data. Some of the commonly used algorithms for symmetric cryptography include AES (Advanced Encryption Standard), DES (Data Encryption Standard), and Blowfish.
A typical use case for symmetric cryptography is encrypting data stored on a hard drive or transmitted over a secure network. For example, when a user wants to store sensitive data on their computer, they can encrypt the data using a symmetric encryption algorithm and a secret key. The same key can then be used to decrypt the data when needed.
Another use case for symmetric cryptography is securing communication between two parties who share a secret key. For example, a company might distribute a secret key to its employees for use in encrypting and decrypting sensitive data.
One case study of symmetric cryptography is the use of WPA2 for wireless network security. WPA2 uses a shared secret key to encrypt and decrypt data transmitted over a wireless network. This enables secure communication over the wireless network, such as online gaming, streaming video, and file sharing.