S/MIME (Secure/Multipurpose Internet Mail Extensions): it is a standard for secure email communication. In other words, its a kind of protocol that gives you option to encrypt your email messages, so you can read it in the peace of your home, and digitally sign it to use confidentiality, integrity and authenticity.
How S/MIME Works:
Security: For S/MIME, “public-key cryptography” is used to encrypt emails sent. Sender encrypts the message with receiver public key. The message can only be decrypted by the person who has its private key.
Digital Signatures: Through S/MIME, a user can digitally sign his/her email message before sending it. Also, this signature allows to identify the true orderer of the message as well as to check whether it has been untampered with.
Key Benefits of S/MIME:
Confidentiality: Provides privacy in email blocks through message encryption
Integrity — guarantee that the message was not modified in transit
Authentication: It is used to check the identity of sender and genuineness of the message.
Non-repudiation — makes sure that sender cannot reject the sending of the message.
How to Use S/MIME:
In order to be able to use S/MIME you must first obtain a digital certificate. It is below-mentioned certificate, which is provided by Certificate Authority (CA) which is trusted and that contains your public key. An email client can create a CSR and send it to the CA. As soon as your certificate is in your hands, you are able to set up your email client to utilize S/MIME
Considerations and Challenges:
Complexity – For large organizations it is rather impractical to implement S/MIME due to its complexity.
User Adoption: Getting users to adopt S/MIME is not easy as it is fairly technical.
Compatibility: Not all email clients and servers support S/MIME.
Conclusion
S/MIME is a great option for securing email exchanges, but it will need to be implemented properly and users will need to get on board with it. With knowledge on pros and cons of S/MIME, organizations can appropriately secure sensitive email communications.
