These are email authentication protocols that use cryptographic algorithms to enhance email security:
DKIM (DomainKeys Identified Mail): Uses cryptographic signatures to verify the sender's domain. SPF (Sender Policy Framework): Allows the sender to specify which IP addresses are authorized to send emails on behalf of their domain. DMARC (Domain-based Message Authentication, Reporting & Conformance): Combines DKIM and SPF to provide a comprehensive email authentication system.