Secure/Multipurpose Internet Mail Extensions (S/MIME)

Question 1

What standard provides cryptographic security for electronic messaging?

Answer 1

S/MIME - Secure/Multipurpose Internet Mail Extensions

Question 2

How does S/MIME work?

Answer 2

It encrypts our emails and their content. It uses separate session keys for each email message sent and received.

A scary side effect of S/MIME is that it can encrypt malware in the email which can pass by firewalls and filters.

Note: We can use digital signatures combined with S/MIME to ensure authentication, integrity, non-repudiation.

Question 3

How do you overcome the risks of using S/MIME?

Answer 3

Email gateways can load up a users private key to decrypt the email before deliver to ensure its safe.

Note: The risk inherently here is that you must give your private key to the email gateway.