A guide to S/MIME Email Signing and Encryption

Email continues to be the primary means of business communication and growing even with the ascendance of other popular productivity messengers. The security risks affecting our emails have increased along with this expansion. Email intrusions are a major concern because, according to a 2022 analysis by PurpleSec 92% of malware was delivered over email.

How can you protect your email communication in the face of these increasing risks? S/MIME (Secure/Multipurpose Internet Mail Extensions) encryption and signature is one practical solution. This article offers a comprehensive overview of S/MIME’s use cases, the problems it addresses, and how to select the best S/MIME certificate for your individual requirements. Additionally, we’ll discuss some recommended email encryption practices.

Getting to Know S/MIME and Its Use Cases

Secure/Multipurpose Internet Mail Extensions, also known as S/MIME, is a widely used protocol that provides an effective way to increase the security of email exchanges. To guarantee email security and integrity, it uses the concepts of public key encryption, a foundational component of contemporary cryptographic systems. A pair of public and private keys, each with a mathematical relationship to the other, are used in public key encryption. The email is encrypted using the public key and the email can only be decoded with the associated private key. This makes sure that even if an email is intercepted while in transit, only the intended recipient may see the information.

S/MIME has a wide range of applications and use cases that address several facets of email security:

  1. Confidentiality: S/MIME encryption is intended to prevent unauthorized access to sensitive information within emails while they are in transit. S/MIME makes sure that sensitive material is kept private and only accessible to the intended receivers, whether it be personal information, trade secrets, financial information, or any other kind of sensitive data.

  2. Authentication: Email spoofing is a common malicious technique where attackers send emails that look to be from reliable sources to steal sensitive data. S/MIME combats this by offering a method for sender authentication.

  3. Data reliability: It is not unusual for data to be changed purposefully (by attackers) or unintentionally (due to transmission faults) during transmission. This problem is resolved by S/MIME, which makes sure that email content is not altered while in transit. It gives the email a digital signature that may be used to confirm that the sent and received messages are identical.

  4. Non-repudiation: In some situations, it may be vital to have unquestionable evidence of an email’s origin. The promise of non-repudiation is that no one can, in this example, deny sending an email. This assurance is provided by S/MIME, which affixes a distinctive digital signature to every email, verifying its origin and boosting receivers’ trust in the email’s source.
To handle many facets of safe digital communication, S/MIME offers a comprehensive suite of email security capabilities in addition to encryption. Due to these characteristics, it is a crucial piece of equipment for any organization’s cybersecurity toolset.

Issues Resolved by Email Signing and Encryption

S/MIME email encryption and signature provide thorough fixes for a variety of issues frequently related to email security. Here are some of the main issues that S/MIME can help solve in more detail:

  1. Phishing attempts: Phishing attacks are attempts by attackers to coerce email recipients into divulging private information like login credentials or credit card data, frequently by seeming to be a reliable organization. The capability of S/MIME to authenticate the sender’s identity is one of its advantages. S/MIME considerably reduces the chance of being a victim of phishing emails by providing a means to verify that an email is, in fact, from the person or entity it claims to be from.

  2. Attacks using the “Man in the Middle”: Man-in-the-middle (MitM) assaults entail an attacker discreetly listening in on two parties who think they are speaking directly to each other and potentially changing the message. Your emails’ content is encrypted using S/MIME so that anyone without the required private key cannot decipher it. This offers a significant defense against MitM attacks by making it nearly hard for an attacker to access or modify emails while they are in route.

  3. Spoofing assaults: Email spoofing is a technique used in spam and phishing campaigns in which the attackers alter an email’s header to make it appear as if its came from a different sender or location than it did. S/MIME creates a strong defense against spoofing attacks by adding a distinct digital signature to every email, guaranteeing that it was not tampered with during transmission and confirming the sender’s identity.

  4. Data security issues: Unauthorized access and the extraction of private data constitute data breaches. They may result in severe consequences, such as monetary loss or reputational harm to a business. Even if someone manages to obtain the email data, sensitive material is protected by encrypted emails because it is unintelligible to them. As a result, even if there is a data breach, the effects can be greatly reduced because the emails’ actual contents are safe.
The solutions provided by S/MIME address these widespread issues head-on and give consumers a high level of security and assurance in their email communications.

Selecting the appropriate S/MIME certificate

S/MIME certificate selection is a crucial first step in establishing a secure email connection. Each certificate provides a unique level of confidence and is appropriate for particular use cases. The three levels of validation for certificates are as follows:

  1. Domain Validation (DV) certificates confirm that the applicant has administrative control over the domain for which the certificate is requested. This is often accomplished by a simple procedure where the certificate authority sends an email to a domain-related address, and the applicant responds to confirm control. This level of certificate is appropriate for usage by individuals or small organizations where communication encryption is the main priority. Due to its less rigorous verification process, it offers a basic degree of trust and is typically provided swiftly.

  2. Organization Validation (OV) certificates: Certificates with this feature provide a higher level of confidence. The certificate authority confirms the organization’s authenticity and existence in addition to domain ownership. This procedure entails comparing the company to public databases and business registries. For companies or organizations who need to build more trust with their users, OV certificates are a fantastic fit. This certificate includes the name of the organization in the certificate details, giving recipients more assurance.

  3. Individual Validation (IV) Certificates: These certificates validate the identity of an individual. They confirm that the applicant is a real person and has control over the personal information provided. IV certificates are typically used by independent developers or small teams where a basic level of trust is sufficient. This level of certificate ensures the integrity of code by demonstrating that it hasn’t been tampered with since it was signed.

  4. IV and OV Certificates: For some use cases, it might be desirable to combine the assurances of IV and OV in a single certificate. This provides a high level assurance that the code is originating from a verified individual within a confirmed organization. The enhanced level of trust can increase users’ confidence in the integrity and source of the software.
SSL.com provides a range of S/MIME certificates to meet your specific requirements. Understanding your needs will help you select the right certificate and successfully increase the security of your email communications. For cost-effective options, look through the many S/MIME certificates on our product pages and consult our guides for bulk orders. Remember that our team of professionals is always there to help you and provide guidance as you decide what is best for your security needs.

Need help or custom solutions? Contact our Sales team. We’re here to assist with all your online security needs.


Recommended Email Encryption Techniques

It takes more than just using S/MIME encryption to ensure secure email data transfer. It’s a complex procedure that incorporates several best practices:

Establish a strict policy for passwords: Your first line of defense in protecting your emails is frequently a strong password policy. This entails not just using strong passwords but also developing a plan for routine password updates and making sure no passwords are reused. Keep in mind that a strong password should contain a combination of letters, numbers, and symbols. It is advised to stay away from using popular words and evident personal details.

Consistently upgrade your software: Both technology and cybercriminals’ methods of operation are constantly evolving. A known vulnerability in outdated software could provide an opening for attackers. You may guard against such dangers by utilizing the most recent versions of your email client, encryption programs, and other relevant software. Install updates as soon as they are made available because they frequently come with security upgrades for existing flaws.

Inform your group: No matter how strong your security system is, vulnerabilities can still be introduced through human error. By instructing your team on the value of email encryption and how to utilize it properly, this can be lessened. Ensure that everyone is aware of the dangers posed by inadequate security procedures and the possible repercussions of a breach. The likelihood of security breakdowns can be considerably decreased by regular training sessions and reminders.

Make use of a trustworthy S/MIME certificate: Your S/MIME certificate’s reliability is crucial to the security of your emails. Choose a certificate from a reputable Certificate Authority (CA), such as SSL.com, as a result. Our certificates follow strict industry standards and can give recipients the trust they need regarding the security of your email.

Make a copy of your encryption keys: If you misplace your encryption keys, you won’t be able to enter your home. If your encryption keys are lost, you won’t be able to decrypt your communications, which could result in irreversible data loss in the case of email encryption. You can recover your encrypted data, if necessary, by routinely backing up your keys in a safe place. You can dramatically improve the security of your email communications by following these best practices. We hope that this tutorial has clarified the significance of S/MIME email encryption and signing for you and assisted you in selecting the best certificate for your requirements. With these technologies, you’re well on your way to a more secure email communication environment. At SSL.com, we’re dedicated to making the online world safer.

Final Thoughts

Email has developed into a vital communication tool, thus maintaining its security is crucial. Through the provision of confidentiality, authentication, data integrity, and non-repudiation, S/MIME email encryption and signing provide solid solutions to improve the security of your email exchanges. Implementing S/MIME and adhering to suggested best practices are efficient ways to safeguard your company from the plethora of email-related security risks.

Your Route to SSL.com-Based Email Security

At SSL.com, we are dedicated to offering complete security solutions catered to your unique requirements. With our selection of S/MIME certificates, which range from Domain Validation to Extended Validation, you can be sure to discover the best option for your business. By choosing SSL.com, you not only select reliable, high-quality certificates but also a partner who is committed to meeting your security needs. Our knowledgeable customer service staff is always available to help and advise you as you choose the best course of action for your security requirements. Start the process of improving your email security today. To learn more about our S/MIME certificates, visit our product page or get in touch with our staff in the form below. Secure email communication is easy to access with SSL.com.  

Planning to secure your emails in bulk? Our streamlined process makes it simple and efficient.

Visit our bulk order guide for more information or proceed to the form below to get started.


Subscribe to SSL.com’s Newsletter

Don’t miss new articles and updates from SSL.com

Stay Informed and Secure

SSL.com is a global leader in cybersecurity, PKI and digital certificates. Sign up to receive the latest industry news, tips, and product announcements from SSL.com.

We’d love your feedback

Take our survey and let us know your thoughts on your recent purchase.