November 14, 2024 Sam Bocetta
From sharing critical documents to coordinating with remote teams, we rely on email more than ever to keep our organizations running smoothly. In fact, research shows that office workers receive 120 emails per day, on average.
Unfortunately, this reliance on email comes with a significant risk of cyberattacks – phishing scams, data breaches, impersonation, you name it. Just last year, email-based phishing scams cost businesses worldwide over $2.9 billion in losses.
Thankfully, there’s a powerful tool that can help safeguard your email communications, and that’s S/MIME digital certificates. Let’s take a look at how you can use it to erect a formidable barrier against the growing tide of email-based threats.
- What are S/MIME Certificates?
- The Role of S/MIME in Email Encryption
- Implementing S/MIME in Your Organization
- Best Practices for Using S/MIME
What are S/MIME Digital Certificates?
S/MIME, or Secure/Multipurpose Internet Mail Extensions, adds a layer of security to your email communications by using digital certificates to keep the content of your emails private and authenticate the sender’s identity.
This means that only the intended recipient can read your message, and they can be confident that it indeed came from you. In particular, three key components govern S/MIME technology:
- Encryption: S/MIME uses cryptographic algorithms to scramble email contents, ensuring that only authorized parties can access the information. This safeguards sensitive data like financial reports, HR records, and intellectual property from prying eyes.
- Authentication: By verifying the sender’s identity through a digital certificate, S/MIME mitigates the risk of email spoofing and impersonation attacks. Recipients can have confidence that the message is from who it claims to be.
- Integrity: S/MIME digital signatures act as a digital “fingerprint,” allowing recipients to detect if a message has been tampered with. This protects the reliability and trustworthiness of your business communications.
Compared to other email security encryption standards S/MIME offers a more comprehensive and user-friendly approach.
S/MIME certificates provide a centralized, standardized way to secure emails end-to-end without the need for complex key management or third-party file-sharing platforms.
The Role of S/MIME in Email Encryption
When you compose an S/MIME-secured email, your email client generates a random, one-time symmetric encryption key. This key is then used to encrypt the message’s contents using a strong algorithm like AES. The symmetric key itself is then encrypted using the recipient’s public key, which is extracted from their S/MIME certificate.
On the receiving end, the recipient’s email client uses their private key (stored securely on their device) to decrypt the symmetric key. This, in turn, allows them to decrypt the message and view its contents in plain text.
The main advantage of this approach is that it combines the speed and efficiency of symmetric encryption with the trust and non-repudiation of asymmetric encryption. Furthermore, the recipient can be confident that the message comes from a verified source and has not been tampered with, while the content itself remains shrouded from prying eyes.
For businesses, the benefits of S/MIME-encrypted emails are manifold. Sensitive information
like financial data, product details, and HR records can be shared securely, reducing the risk of data breaches and intellectual property theft.
Authenticating the Sender With S/MIME
Beyond encryption, S/MIME plays a vital role in verifying the identity of email senders, a crucial defense against the growing threat of phishing attacks and other email-based threats. When you send an email with S/MIME, your digital certificate is used to create a digital signature. This signature acts as a tamper-evident seal, assuring recipients that the message originated from the claimed source and has not been altered in transit.
Firstly, the sender’s email client uses their private key to generate the digital signature, which is then attached to the outgoing message. On the receiving end, the recipient’s email client checks the signature against the sender’s public key (extracted from their digital certificate) to confirm the message’s authenticity.
Through the verification of the sender’s identity, S/MIME helps recipients distinguish legitimate emails from fraudulent ones, reducing the risk of falling victim to these costly attacks.
Implementing S/MIME in Your Organization
Before diving into S/MIME implementation, it’s important to note that using private email services is a prerequisite if this is to work properly.
Assuming you already have secure private email infrastructure in place, the first step to implementing S/MIME is to obtain S/MIME digital certificates for your organization. These can be purchased from trusted Certificate Authorities (CAs) like GlobalSign.
GlobalSign will verify your organization’s identity and issue the necessary certificates, which you can then install on your email servers and client devices.
Once the certificates are in place, you’ll need to configure your email software to utilize the S/MIME functionality. This typically involves enabling S/MIME in your email client’s settings and associating the appropriate certificate with your email account.
Best Practices for Using S/MIME
To ensure the maximum effectiveness of your S/MIME implementation, it’s important to establish clear policies and guidelines for its usage throughout your organization, which may include:
- Mandating the use of S/MIME for all sensitive or confidential email communications
- Providing training to employees on properly sending and verifying S/MIME-secured messages, spotting malicious emails and subsequently handling them
- Implementing processes for the timely revocation of certificates in case of employee turnover or security breaches
- Educating your team on the importance of safeguarding their private keys, as losing them can compromise the security of encrypted emails
- Regularly reviewing and updating your S/MIME policies to keep pace with evolving threats and technological advancements
However, it’s also important to be aware of the fact that the implementation of S/MIME is only an introduction to its further maintenance. To help with that, you can source insights from other departments and workflows from within the organization.
Reinforcing S/MIME Implementation with Additional Insights
While most companies focus on threat severity and adjacent data, the best way to implement S/MIME is to bolster it from external insights, such as:
- Threat intelligence feeds: Stay informed about the latest email-based threats and the cutting-edge ML-based methods of combating them. This information can help you optimize your S/MIME configuration and usage to better defend against emerging risks.
- Penetration testing reports: Utilize findings from penetration testing reports to identify vulnerabilities in your email infrastructure that S/MIME can subsequently help address.
- Email security audits: Conduct periodic audits of your email security posture, including how S/MIME certificates are being used across your organization. These audits can help identify areas where certificate usage can be optimized.
Incorporating these additional information sources into your S/MIME strategy can create a more robust and adaptive email security posture.
For example, if penetration testing reveals that certain email accounts are more vulnerable, you might prioritize implementing or enforcing S/MIME encryption and digital signatures on those accounts to bolster security.
Integrating S/MIME With Existing Email Security Protocols
While S/MIME offers comprehensive protection for email communications, it’s often beneficial to integrate it with other security measures already in place. A particularly popular mix is combining S/MIME with TLS, as it ensures that both the content and the transmission path are secure.
Additionally, implementing spam filters and anti-phishing tools alongside S/MIME can provide a multi-faceted defense against various email threats.
Thus, by integrating S/MIME into your broader email security strategy, you create a more robust and resilient communication environment for your organization.
Wrapping Up
In an era where business email compromise poses an ever-growing threat, adopting S/MIME is becoming increasingly crucial. However, it’s not merely about enhancing email security; it’s about building trust with clients, partners, and colleagues.
Looking ahead, the role of S/MIME in email security is only poised to grow. As hackers continue to refine their tactics, organizations that invest in this technology will be better equipped to stay one step ahead, safeguarding their communications and protecting their most valuable digital assets.
Discover more about GlobalSign’s S/MIME solution
Note: This blog article was written by a guest contributor for the purpose of offering a wider variety of content for our readers. The opinions expressed in this guest author article are solely those of the contributor and do not necessarily reflect those of GlobalSign.
Sam Bocetta
Sam Bocetta is a cyber-authority with over 25 years of experience and a comprehensive understanding of fraud, identity theft, and privacy issues that plague millions of victims worldwide.