What is S/MIME? Email security measures!

subornaakter20 · Post by **subornaakter20** » Sat Feb 01, 2025 9:32 am

2017-08-02(Updated: 2024-12-10 )
Security measures

Recently, I feel like I've been getting more and more security-related questions during meetings.

I hope that after reading this column, you will medical mail list take another look at the security of email delivery .

This time, we will be talking about "S/MIME", a security measure adopted by many financial institutions!!

Table of Contents [Hide]

1. What is S/MIME?
2. Authentication using digital signatures
3. What is encryption?
4. How do I send emails that support S/MIME?

What is S/MIME?
"S/MIME" is a standard (rule) for authentication and email encryption using electronic signatures on email systems .

By using a digital certificate issued by a trusted third-party certification authority, it is possible to encrypt the email you send, add an electronic signature to it, and send emails with an electronic signature.

"STARTTLS", which I introduced in another column, encrypts [communications], but "S/MIME" makes it possible to encrypt [the email itself].

What is STARTTLS? Introducing the mechanism for encrypting emails
"STARTTLS" is a mechanism for encrypting communication when sending email. Specifically, it encrypts communication from the sending mail server to the receiving mail server. This prevents the email body from being stolen, tampered with, or hacked during communication.
Alala Message

By using "S/MIME", you can avoid the following three risks.

E-mail content being intercepted by a third party
Falsification of email content by a third party
A third party spoofing the email sender
*"S/MIME" is an abbreviation for Secure/Multipurpose Internet Mail Extensions.

What is authentication using digital signatures?
This is an effective countermeasure against "spoofing," where a third party pretends to be the sender of an email.

This uses a mechanism called an "electronic signature" that guarantees that an email was sent by the actual sender, and determines the trustworthiness of the email sender.