How does public-key cryptography work?

Public-key cryptography uses pairs of related public and private keys generated via one-way mathematical functions. While the public key can be openly shared to encrypt data or verify signatures, the private key must be kept secret to ensure security. This asymmetric approach underpins modern Internet security standards, often combined with symmetric cryptography for efficiency.

What we know

• Public-key cryptography utilizes key pairs consisting of a public key and a corresponding private key. [1, 2]
• Key pairs are generated using algorithms based on mathematical problems known as one-way functions. [2]
• The security of the system relies on keeping the private key secret while allowing the public key to be openly distributed. [2]
• Public-key cryptography is also known as asymmetric cryptography. [1, 2]
• The invention of public-key cryptography helped bring secure cryptography out of government exclusivity and into the public domain. [4]

Where to go next

• compared withWhat is symmetric cryptography?
• how it workedHow do cryptographic hash functions work?
• whenWhat is the history of cryptography?
• what followedHow does Transport Layer Security use keys?
• a case in pointWhat is a public key fingerprint?
• an unexpected connectionHow did breaking World War II ciphers change history?Although modern public security relies on asymmetric math, the broader history of cryptography includes manual and mechanical ciphers whose wartime interception altered global conflicts long before public keys existed.

Sources

• [1]public-key cryptography (Wikidata Q201339) · CC0 1.0
• [2]Public-key cryptography · CC BY-SA 4.0
• [3]Key (cryptography) · CC BY-SA 4.0
• [4]History of cryptography · CC BY-SA 4.0
• [5]Public key fingerprint · CC BY-SA 4.0