Alt-N Technologies DKIM Project
The DKIM project is a portable library that signs and verifies emails using the OpenSSL library.
To acquire the Alt-N DKIM open source toolkit
click here.
To review the current DKIM working drafts click here
and scroll down to the Specifications section.
What is DKIM?
DomainKeys Identified Mail (DKIM) defines a domain-level authentication framework for email using
public-key cryptography and key server technology to permit verification of the source and contents of
messages by either Mail Transport Agents (MTAs) or Mail User Agents (MUAs).
Ok..., what does that mean?
Let's break it down into chunks:
... domain-level authentication framework for email
DKIM uses DNS to store the public key and policy information. This information can be used to
validate an identity associated with an email message.
using public-key cryptography and key server technology
The DKIM signing algorithm computes a SHA-1 hash of the message header and body and
encrypts it using the RSA algorithm and the private key. This
signature is stored in the DKIM-Signature: header of the email.
permit verification of ...
DKIM uses the public key from DNS to decrypt the signature and compares the hash
to one computed from the email message.