Email and domain security are critical aspects of maintaining the integrity and confidentiality of communications in the digital age. With the increasing prevalence of cyber threats such as phishing and spoofing, understanding the terminology related to email security is crucial. This glossary provides a comprehensive overview of key terms and concepts that are fundamental to email and domain security.
DMARC (Domain-based Message Authentication, Reporting & Conformance)
DMARC is an email authentication protocol that builds on SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) to ensure that emails are properly authenticated against established policies. DMARC allows domain owners to specify how unauthenticated emails should be handled and provides a reporting mechanism for feedback on authentication performance.
DMARC Policy
A DMARC policy defines how an email server should handle emails that fail DMARC authentication checks. Policies can be set to `none` (no action, only reporting), `quarantine` (mark emails as suspicious), or `reject` (outright block the emails).
DMARC Alignment
DMARC alignment ensures that the domain in the ‘From’ address matches the domains used in SPF and DKIM. This alignment can be either strict or relaxed:
– **Strict Alignment**: Requires an exact match.
– **Relaxed Alignment**: Allows subdomain matches.
SPF (Sender Policy Framework)
SPF is an email validation protocol designed to detect and prevent spoofing. It allows domain owners to specify which IP addresses are authorized to send emails on behalf of their domain. The receiving mail server checks the SPF record to verify if the email is sent from an authorized source.
DKIM (DomainKeys Identified Mail)
DKIM is an email authentication method that uses digital signatures. The sending mail server signs the email with a private key, and the receiving mail server uses the corresponding public key (published in the DNS) to verify the signature. This ensures that the email has not been altered in transit and confirms the sender’s identity.
DKIM Selector
A DKIM selector is a string that allows the domain owner to have multiple keys for signing emails. The selector is specified in the email header and helps the receiving mail server locate the correct public key in the DNS to verify the signature.
RUA (Reporting URI for Aggregate Reports)
RUA is an address specified in a DMARC record to which aggregate reports are sent. These reports provide detailed information about the emails that passed or failed DMARC checks, helping domain owners understand how their domain is being used and identifying potential abuse.
RUF (Reporting URI for Forensic Reports)
RUF is an address specified in a DMARC record to which forensic (detailed, real-time) reports are sent. These reports include information about individual emails that failed DMARC checks, providing insight into specific instances of authentication failures.
Spoofing
Spoofing is a technique used by attackers to send emails that appear to come from a trusted source. This is typically done to trick recipients into divulging sensitive information or clicking on malicious links. Spoofing can be mitigated by implementing SPF, DKIM, and DMARC.
Phishing
Phishing is a cyberattack that involves sending fraudulent emails designed to trick recipients into revealing personal information, such as passwords or credit card numbers. Phishing emails often appear to come from legitimate sources and can lead to significant financial and data losses.
BEC (Business Email Compromise)
BEC is a sophisticated email scam targeting businesses. Attackers impersonate company executives or trusted partners to trick employees into making unauthorized wire transfers or revealing confidential information. BEC attacks often involve extensive research and social engineering.
TLS (Transport Layer Security)
TLS is a cryptographic protocol designed to provide secure communication over a computer network. It is widely used to encrypt emails in transit, ensuring that the contents cannot be intercepted or tampered with.
S/MIME (Secure/Multipurpose Internet Mail Extensions)
S/MIME is a protocol for sending encrypted and digitally signed emails. It provides end-to-end security by ensuring that only the intended recipient can read the email and verifying the sender’s identity through digital signatures.
ARC (Authenticated Received Chain)
ARC is an email authentication system designed to allow intermediate mail servers to forward authenticated messages without breaking the chain of authentication. It helps preserve the results of SPF, DKIM, and DMARC checks, even when emails pass through multiple servers.
BIMI (Brand Indicators for Message Identification)
BIMI is an emerging email specification that allows brands to display their logos in email clients, enhancing brand recognition and trust. BIMI requires the use of DMARC to ensure that only authenticated emails can display the brand logo.
DNSSEC (Domain Name System Security Extensions)
DNSSEC is a suite of extensions to DNS that adds security to the domain name resolving process. It enables DNS responses to be verified, ensuring that they have not been tampered with and come from a legitimate source. DNSSEC protects against various attacks, such as cache poisoning and man-in-the-middle attacks.
Registrar Lock
Registrar lock is a security feature provided by domain registrars to prevent unauthorized changes to a domain name. When a domain is locked, it cannot be transferred, deleted, or have its contact information modified without the registrar’s intervention. This helps prevent domain hijacking and unauthorized domain transfers.
Registry Lock
Registry lock is a higher level of domain security that involves the domain registry itself. This lock is typically used for high-value domains and requires multiple levels of authentication and authorization before any changes can be made to the domain. It provides an additional layer of security beyond the registrar lock, protecting against unauthorized changes and transfers.
Understanding these key terms and concepts is essential for anyone involved in managing email and domain security. By implementing protocols like SPF, DKIM, and DMARC, organizations can protect their domains from abuse, reduce the risk of phishing and spoofing, and maintain the integrity of their communications. Regularly reviewing reports and staying informed about the latest security practices will help ensure robust email security in the ever-evolving digital landscape.
