Asymmetric key

Glossary Term Asymmetric key

An asymmetric key, also known as a public key, is a cryptographic key that comes in a pair: a public key and a corresponding private key.

  • Public Key: This key is freely shared with anyone. It’s used to encrypt data.
  • Private Key: This key is kept secret and known only to the owner. It decrypts data encrypted with the corresponding public key.

Key Characteristics:

  • Asymmetrical: The key pair works in one direction only. Data encrypted with the public key can only be decrypted with the corresponding private key.
  • Mathematically Related: The public and private keys are mathematically linked, but it’s computationally infeasible to derive the private key from the public key.
  • Wide Applications: Asymmetric key cryptography has numerous applications, including:
    • Secure Communication: Enables secure communication channels like HTTPS (Secure Sockets Layer) for secure web browsing.
    • Digital Signatures: Allows for the verification of the authenticity and integrity of digital documents.
    • Key Exchange: Used to securely exchange symmetric encryption keys over an insecure channel.

Examples:

  • HTTPS: When you visit a secure website (indicated by “https” in the address bar), your browser uses the website’s public key to encrypt the communication. The website then uses its private key to decrypt the information.
  • Digital Signatures: When you sign a document digitally, you use your private key to create a digital signature. Others can then use your public key to verify the authenticity of the signature.
  • Public Key Infrastructure (PKI): PKI is a system for creating, managing, and distributing digital certificates, which contain public keys and other information.

Advantages of Asymmetric Key Cryptography:

  • Secure Key Exchange: Eliminates the need to securely share a secret key, which can be challenging in many scenarios.
  • Authentication: Enables digital signatures, allowing for the verification of the origin and integrity of data.
  • Wide Range of Applications: Used in various applications, from secure communication to digital signatures and authentication.

Disadvantages: