Email is a crucial part of our daily lives, but unfortunately, it’s also a popular target for cybercriminals who use various tactics like spam, phishing, and spoofing to scam people. The FTC recently issued a warning to users of MetaMask and PayPal about phishing scams that are currently circulating through fake emails. The scam claims that the user’s cryptocurrency wallet has been blocked and encourages them to click a link and update their wallet to prevent the loss of their crypto. To protect email users from these threats, authentication protocols like DKIM, SPF, and DMARC are strongly recommended.

In this blog post, we’ll explore the differences between these protocols in a simpler way.

What is DKIM?

DKIM (DomainKeys Identified Mail) is an email authentication method designed to detect email spoofing. It uses a cryptographic signature to verify that the email message received by the recipient was sent by the domain it claims to be from.

To implement DKIM, the domain owner generates a public-private key pair where the private key is kept confidential, and the public key is shared in their DNS records. When an email is sent from the domain, the sender’s email server adds a signature to the message using the private key. The receiving email server then checks the public key in the domain’s DNS records and verifies the signature to ensure that the message is authentic and hasn’t been tampered with.

What is SPF?

SPF (Sender Policy Framework) is an email authentication protocol that verifies the sender’s IP address against a list of authorized IP addresses published in the domain’s DNS records.

To implement SPF, the domain owner creates a DNS record that lists all the authorized IP addresses that can send emails on behalf of the domain. When an email is received, the recipient’s email server checks the SPF record in the domain’s DNS to confirm that the sender’s IP address is authorized to send emails on behalf of that domain.

What is DMARC?

DMARC (Domain-based Message Authentication, Reporting, and Conformance) is an email authentication protocol that combines DKIM and SPF to provide better protection against email fraud. DMARC allows domain owners to publish a policy in their DNS records that instructs receiving email servers on how to handle emails that fail authentication checks.

DMARC works by telling the receiving email server to check both the DKIM and SPF records for the domain and take specific actions based on the authentication results. The DMARC policy can instruct the receiving server to quarantine or reject emails that fail authentication checks or allow them to be delivered with a warning message.

The Differences between DKIM, SPF, and DMARC

The main differences between these protocols are as follows:

Verification Method

DKIM uses a digital signature while SPF verifies the sender’s IP address against a list of authorized IP addresses.

Type of Attack Detected

DKIM can detect email spoofing and tampering, while SPF only verifies that the sender’s IP address is authorized to send email on behalf of the domain.

Implementation

DKIM and SPF require the domain owner to publish DNS records that specify the rules for email authentication. DMARC requires the domain owner to publish a DMARC policy in their DNS records that instructs receiving email servers on how to handle emails that fail authentication checks.

Result Handling

DMARC provides more control over how email that fails authentication checks is handled. The DMARC policy can instruct receiving servers to quarantine or reject emails that fail authentication checks, or to allow them to be delivered with a warning message.

It’s important to note that while DKIM, SPF, and DMARC are essential tools to protect against email fraud, they are not a panacea for all email scams or business email compromise (BEC). BEC attacks, for instance, use social engineering tactics and impersonation techniques to trick victims into transferring funds or sensitive information to the attacker. These types of attacks can be more difficult to detect and prevent using authentication protocols alone.

Therefore, in addition to implementing authentication protocols, it’s crucial to educate email users on how to identify and report suspicious emails. This includes checking email addresses, scrutinizing links and attachments, and being wary of urgent or unusual requests. By combining these best practices with authentication protocols, individuals and organizations can create a multi-layered approach to protect against email fraud and cybercriminals.