Public Key Cryptography and Digital Signatures

Public Key Infrastructure

System ensuring secure data exchange via keys; framework for managing digital certificates and encryption.

Digital Signature

Mathematical technique for authenticity and integrity; confirms authenticity of a message sender.

Authentic Signature

Proof that only the signer signed the document.

Unalterable Signature

Document cannot be changed post-signature.

Not Reusable Signature

Signature cannot transfer to another document.

Non-repudiated Document

Signed document equates to a physical signature; Prevents denial of signing a document.

Code Signing

Verifying executable files with digital signatures; Process of digitally signing software to verify authenticity.

Digital Certificates

Electronic documents proving ownership of public keys.

Digital Signature Standard (DSS)

Standards for generating and verifying digital signatures.

Digital Signature Algorithm (DSA)

Original standard for public/private key pairs; Digital Signature Algorithm for secure digital signatures.

Rivest-Shamir-Adelman Algorithm (RSA)

Asymmetric algorithm for digital signatures; Rivest-Shamir-Adleman, a widely used public-key algorithm.

Elliptic Curve Digital Signature Algorithm (ECDSA)

Efficient digital signature algorithm with small sizes; Elliptic Curve Digital Signature Algorithm for efficient signatures.

Integrity

Assurance that data has not been altered.

Authenticity

Verification that data comes from a legitimate source.

Certification Path

Chain of trust from signer to trusted authority.

DigiCert

Trusted certificate authority for digital signatures; Commercial CA providing SSL certificates.

How are digital signatures created

using various mathematical techniques

Public Key

Key used for encrypting data in PKI; Used to verify digital signatures and encrypt messages.

Private Key

Key used for decrypting data in PKI.

Digital Certificate

Authenticates and verifies user identity in communications.

Hash Value

Fixed-size output from hashing a document.

SSL Certificate

Confirms identity of a website domain.

Certificate Authority (CA)

Trusted entity that issues digital certificates; Entity that issues digital certificates for identity verification.

Asymmetric Connection

Connection using a pair of public and private keys.

Credential Issuance

Process of issuing digital certificates by CAs.

Trusted Third Party

Entity that validates and issues digital credentials.

Certificate Validation

Process of confirming the authenticity of a certificate.

In-depth Investigation

CA's process to verify identity before issuing certificates.

Hash Comparison

Checks if received document hash matches decrypted signature.

GlobalSign

CA providing digital certificates for various needs.

Sectigo

CA offering SSL and other digital certificates.

Public Key Management

Process of exchanging and managing public keys.

Class 0 Certificate

Testing certificate with no identity checks performed.

Class 1 Certificate

Email verification for individual users.

Class 2 Certificate

Identity proof required for organizations.

Class 3 Certificate

Used for server and software signing.

Class 4 Certificate

For online business transactions between companies.

Class 5 Certificate

Used for private organizations or government security.

Single-root PKI Topology

Single CA issues all certificates within an organization.

Cross-certified CA Topology

Multiple CAs linked for broader trust relationships.

Hierarchical CA Topology

Structured CA system with parent-child relationships.

Interoperability

Ability of different PKI systems to work together.

Lightweight Directory Access Protocol (LDAP)

Protocol for accessing directory services over a network.

Self-signed Certificate

CA's public key used to verify issued certificates.

Certificate Enrollment Process

Process for a host system to register with PKI.

Certificate Revocation List (CRL)

List of certificates that have been revoked.

Online Certificate Status Protocol (OCSP)

Real-time protocol for checking certificate status.

Authentication

Process of verifying the identity of a user.

Certificate Exchange

Users share certificates containing their public keys.

SSL/TLS

Protocol for secure communication over a computer network.

IPsec VPNs

Secure network traffic using Internet Protocol Security.

HTTPS

Secure version of HTTP using SSL/TLS encryption.

802.1x authentication

Network access control protocol for port-based access.

S/MIME

Secure email protocol for encrypting and signing messages.

Encryption File System (EFS)

Windows feature for encrypting files on NTFS volumes.

Two-factor authentication

Security process requiring two forms of verification.

Smart cards

Physical cards used for secure authentication.

USB storage security

Protecting data on USB devices from unauthorized access.

Signature validation error

Failure to verify certificate authenticity due to issues.

Root certificate

Top-level certificate in a certificate authority hierarchy.

CRLs

Certificate Revocation Lists for invalidating certificates.

OCSP

Online Certificate Status Protocol for real-time certificate validation.