What are Public-Key Encryption Algorithms? (2024)

FAQs

What is the public key encryption algorithm? ›

What is public key cryptography? Public key cryptography is a method of encrypting or signing data with two different keys and making one of the keys, the public key, available for anyone to use. The other key is known as the private key. Data encrypted with the public key can only be decrypted with the private key.

Public key encryption is a highly secure encryption scheme that in which a single shared key is used by both the sender and receiver of the message.

Public key encryption uses a pair of keys: a public key for encryption and a private key for decryption. The sender uses the public key to encrypt the message, and receiver uses their private key to decrypt it.

The most commonly used public-key cryptosystem is RSA, which is named after its three developers Ron Rivest (b. 1947), Adi Shamir, and Leonard Adleman (b. 1945). At the time of the algorithm's development (1977), the three were researchers at the MIT Laboratory for Computer Science.

The secret key mechanism is called symmetric being a single key between two parties. The public key mechanism is known as asymmetric as its two keys are used for different purposes. The secret key is shared between two parties. The public key can be used by everyone.

RSA is an example of a public key encryption algorithm used for secure communication and data exchange.

Today's cryptosystems (such as TLS, Secure Shell) use both symmetric encryption and asymmetric encryption, often by using asymmetric encryption to securely exchange a secret key, which is then used for symmetric encryption.

Unlike symmetric encryption, which uses the same secret key to encrypt and decrypt sensitive information, asymmetric encryption, also known as public-key cryptography or public-key encryption, uses mathematically linked public- and private-key pairs to encrypt and decrypt senders' and recipients' sensitive data.

Digital Signatures: Public and private keys can be used to create a digital signature, which assures that the person sending the message is who they claim to be. Typically, the recipient's public key is used to encrypt the data and the recipient then uses their private key to decrypt the data.

Definitions: The public part of an asymmetric key pair that is typically used to verify signatures or encrypt data. A cryptographic key that is used with an asymmetric (public key) cryptographic algorithm and is associated with a private key.

How to make a public key encryption? ›

Public keys are important because they help protect sensitive information and send it securely. For example, imagine sending a confidential letter that's only intended for the recipient, you might consider sending the letter in a locked box, but you would also have to send the key.

Example: Public keys of every user are present in the Public key Register. If B wants to send a confidential message to C, then B encrypt the message using C Public key. When C receives the message from B then C can decrypt it using its own Private key.

Anyone can encrypt a message by using your public key, but only you can read it. When you receive the message, you decrypt it by using your private key. Similarly, you can encrypt a message for anyone else by using their public key, and they decrypt it by using their private key.

AES is a symmetric key algorithm, which means there is just one key, used both to encrypt and decrypt. This is different from RSA, where you have two keys - a private one and a public one, related in a specific way. AES keys are simply random bytes. For example, AES-128 uses 128-bit (16 byte) keys.

RSA (Rivest–Shamir–Adleman) is a public-key cryptosystem, one of the oldest widely used for secure data transmission. The initialism "RSA" comes from the surnames of Ron Rivest, Adi Shamir and Leonard Adleman, who publicly described the algorithm in 1977.

The RSA algorithm (Rivest-Shamir-Adleman) is the basis of a cryptosystem -- a suite of cryptographic algorithms that are used for specific security services or purposes -- which enables public key encryption and is widely used to secure sensitive data, particularly when it is being sent over an insecure network such as ...