The terms public key and private key are frequently used in the field of encryption and decryption. They play a significant role in securing sensitive information and critical data.
Cryptography, the art of writing and storing confidential data, is divided into several categories, namely hashing, symmetric, and asymmetric cryptography. A clear distinction exists between a public key and a private key, which we will explore in this article. But first, let's delve a little deeper into the concepts.
Defining a Private Key
A private key is a tool that allows a user to both encrypt and decrypt data. Shared between the sender and receiver of encrypted information, this key is also known as a symmetric key because it is common to both parties. In other words, the same encryption key is copied or shared by the other party to decrypt the ciphertext.
Furthermore, the mechanism of a private key is significantly faster than public-key cryptography. In the case of a private key, the same key is utilized for both encryption and decryption.
Understanding a Public Key
A public key, on the other hand, is used to encrypt data, while the private key is used for decryption. Simply put, a user can encrypt data using a single (public) key, and then the receiver uses a private key to decrypt the ciphertext and read the message. This is also referred to as asymmetric cryptography.
Contrasting Private Key and Public Key
Below is a comparison of the Private Key and Public Key.
Parameters
Private Key
Public Key
Algorithm Implemented
A private key is used for both encryption and decryption of data, hence it is shared between the sender and receiver.
A public key is solely used to encrypt data, and a shared private key is required for its decryption.
Efficiency
The mechanism here is considerably faster.
The mechanism here is comparatively slower.
Key Type
The process is symmetric as a single key is shared between the sender and receiver.
It is asymmetric because two different keys are needed for encryption and decryption.
Confidentiality
The private key is kept secret from users, and only the sender and receiver have access to it.
The public key is freely accessible and usable by the public. However, only the sender and receiver possess the private key needed for decryption.
Sharing
A private key needs to be shared between the sender and receiver.
The public key can be used by anyone, but a private key is required for decryption.
A private key is a type of key that allows a user to encrypt and decrypt the available data. It is shared between the receiver and the sender of the encrypted information and is also known as symmetric cryptography.
What is a Public Key?
A public key is a type of key that helps a user encrypt data while the private key decrypts it. It is also known as asymmetric cryptography.
What are the main differences between a Private Key and a Public Key?
Private Keys are used for both encryption and decryption of data and are shared between sender and receiver. They offer faster performance and are part of symmetric cryptography. Public Keys, on the other hand, are used only for encrypting data, with a shared private key needed for decryption. They are part of asymmetric cryptography and offer slower performance.