+3 votes
There are DKIM signatures in emailing which are used for authentication purpose.

Can i know the exact need and use about DKIM signatures ?

asked Apr 25, 2016 in Computer Science - IT by kevin | 122 views

1 Answer

+2 votes
Selected Ans.

DomainKeys Identified Mail (DKIM) is used to authenticate the emails.
if they are not authenticated ones they are redirected to spam.


DKIM help any company who sends email to be responsible for the email they send.

What does DKIM uses for authentication ?

  • Domain name identifier , which is unique to any domain (domains are individual websites)
  • Public key cryptography
  • DNS based public key publishing service

A mail emerging from any domain is signed by Mail user agent or Mail submission agent along the way to sender

Once the email is sent , email provider service (like gmail ) will verify with DNS.

The ultimate goal of this framework is to permit a signing domain to assert responsibility for a message, thus protecting message signer identity and the integrity of the messages.

RFC text : https://www.ietf.org/rfc/rfc4871.txt

Go through FAQ regarding DKIM :


Example DKIM sign : 

DKIM-Signature a=rsa-sha1; q=dns;
s=jun2005.eng; c=relaxed/simple;
t=1117574938; x=1118006938;

where b is signature which is unique to the DNS of sender

answered Jun 3, 2016 by ppk
selected Jun 8, 2016 by kevin