The risks associated with using DKIM mainly consist of private key compromise or failure to properly implement the DKIM protocol. If the private key used for signing emails is compromised, an attacker can potentially forge emails that appear to be legitimate. Moreover, if DKIM is not implemented correctly, it can result in legitimate emails being rejected or classified as spam.
DKIM (DomainKeys Identified Mail) is an email authentication method that uses cryptography to verify the authenticity of an email message. The process involves adding a digital signature to the email header using a private key that only the sending domain has access to. The recipient server then verifies the signature using a public key published in the sending domain’s DNS records.
To implement DKIM, the sending domain generates a public-private key pair and publishes the public key in its DNS records with a special TXT record. When an email is sent, the sending server adds a DKIM-Signature header to the message containing the domain selector and the digital signature of the email message. The recipient server then retrieves the public key from DNS, verifies the signature, and compares it to the domain selector to ensure that the email has not been tampered with during transmission.
