What is a DKIM certificate and how does it increase the security of email communication?

In the world of digital communication, email is one of the most widespread and important tools for personal and professional communication. However, with its proliferation come various security threats such as phishing and spoofing. To combat these threats and ensure the integrity and authenticity of emails, a technology known as DKIM has been developed. In this article, we will look at what a DKIM certificate is, how it works and why it is important.

What is DKIM?

DKIM (DomainKeys Identified Mail) is an email authentication protocol that allows organizations to digitally sign their emails. This signature verifies that the email message was actually sent from an authorized domain and has not been altered in transit.

How does DKIM work?

DKIM works on the principle of asymmetric cryptography, which uses two keys: a private key and a public key.

• Key generation**: The organization generates a pair of cryptographic keys (private and public). The private key is kept secret and used to sign outgoing emails, while the public key is published in the domain's DNS record.
• Email Signing: When sending an email, the message is signed using the private key. This digital signature is added to the email header.
• Authentication: Recipients of the email can use the public key, which is available in the DNS record of the sending domain, to verify that the email was indeed signed with the private key and that it was not altered during transmission.

The DKIM record in DNS contains the public key and other information needed to verify the signature, such as a selector that specifies which public key to use.

Why is DKIM important?

• DKIM helps prevent attackers from sending email that appears to originate from your domain by allowing recipients to verify the authenticity of the message.
• Message Integrity Assurance: DKIM ensures that the email message has not been altered during transmission, protecting the content of the email from unauthorized modifications.
• Improving deliverability**: Emails that are signed and authenticated using DKIM are more likely to be delivered to the recipient's inbox rather than the spam folder, increasing the efficiency of email communications.

DKIM implementation

Implementing DKIM involves several steps:

1. DKIM Key Generation: The organization must generate a private and public key. The private key is securely stored on the email server that will sign outgoing emails.
2. **The public key is published in the domain's DNS record as a TXT record. This record must be available so that receiving servers can verify signatures.
3. Email Server Configuration: The email server is configured to sign all outgoing email using the private key.

Conclusion

DKIM is a key technology for securing email communications, ensuring the authenticity and integrity of email messages. Implementing DKIM can significantly reduce the risk of email attacks such as spoofing and improve the trustworthiness and deliverability of your emails. Combined with other authentication protocols such as SPF (Sender Policy Framework) and DMARC (Domain-based Message Authentication, Reporting & Conformance), DKIM provides strong protection against cyber threats in email communications.