What is Public Key? Understand Public Key in one minute

In asymmetric cryptography, the publicly distributed "public key" allows anyone to encrypt data that can only be decrypted by its corresponding, securely kept "private key."

Oct 25, 2024 at 10:49 pm

What is a Public Key: A Quick Guide

1. Definition:

A public key is a cryptographic value used in asymmetric cryptography, a system where two mathematically related keys are employed for encryption and decryption.

2. Role in Encryption:

• In asymmetric cryptography, one key (the "public key") is used to encrypt plaintext data, making it unreadable to unauthorized parties.
• The encrypted data can only be decrypted using the corresponding "private key," which is kept secret.

3. Generation:

• Public keys are mathematically generated along with their corresponding private keys.
• Both keys are linked and have different values, but they are cryptographically related.

4. Application:

Public keys are widely used in digital security applications, such as:

• Secure email (PGP, S/MIME)
• Digital signatures
• Secure communication (TLS, HTTPS)
• Cryptocurrency transactions

5. Key Features:

• Public: Public keys are distributed publicly and shared with others.
• Encryption: Public keys can only be used to encrypt data, not decrypt it.
• Authentication: Public keys can be used to verify the authenticity of digital signatures and encrypted messages.
• Key Pair: Public keys are always associated with a corresponding private key.

6. Managing Public Keys:

Public keys are typically stored in digital certificates, which contain information about the key holder's identity and the key's validity.

7. Importance:

Public keys play a crucial role in ensuring the security and privacy of sensitive data by providing secure encryption, authentication, and non-repudiation.