SSL Certificate

What is S/MIME Encryption and How Does It Work?

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S/MIME encryption – Let’s understand how S/MIME encryption works and what it is.

Are you wondering what S/MIME encryption is all about? Don’t worry; it is not just you who is unaware of this term. Many internet users are unaware of S/MIME encryption. Many of us send and receive several emails a day, but we may not know that our emails could be accessed and modified by third parties like hackers. They can steal sensitive information that is sent through an email. This is why we will have to encrypt our emails and make sure no one else other than the intended recipient can access our emails. Read on to know how you can secure your emails using S/MIME and how this technology works.

What is S/MIME?

S/MIME stands for “Secure/Multipurpose Internet Mail Extensions.” It’s a technology that is used to encrypt emails. This email signing protocol uses encryption to enhance email security. S/MIME is implemented using S/MIME certificates. This technology will let you sign your emails thereby letting you verify that you are the legitimate sender of the email. This will help your recipients fight off phishing attacks and safeguard your emails from unauthorized access.

How Does S/MIME Encrypt My Email?

S/MIME uses mathematically related public and private keys to operate. This technology is based on asymmetric cryptography. It is close to impossible to find out the private key even if you have the public key. When you use this technology to encrypt your emails, the email you send will be encrypted using the public key of the recipient. Without the corresponding private key, it is impossible to decrypt the email. The intended recipient of the email is the one who will possess the private key. No one other than the intended recipient of the email can read the emails you send or access sensitive attachments you send across. Only if the private key is compromised, hackers or others can access the email you send.

S/MIME will let you sign your emails and establish that you are the legitimate sender of the email. When we say you can sign your email, this does not mean your emails will manually be signed using a pen. This technology will sign your emails digitally. The private key assigned to your email will apply your unique Digital Signature to the email you send. This will be done every time you send an email. The public key will verify your signature when the recipient opens the email you sent. This signature will give the recipient the assurance that you are the legitimate sender of the email and it will also authenticate your identity.

You may wonder why you have to sign your emails. But with the surge in phishing emails and online crimes, it is mandatory to secure sensitive data you send online through an email. It is getting tougher to differentiate between fake and legitimate emails, so it is important to make sure the emails you send do not get into the wrong hands. With a surge in phishing attacks, it is important to verify the identities of the senders of emails. Considering the security features a S/MIME certificate offers, it is wise to implement S/MIME.

Now that you know S/MIME certificates use asymmetric encryption to encrypt emails, let’s understand exactly how a S/MIME certificate works.

How Does a S/MIME Certificate Work?

S/MIME certificates encrypt emails using asymmetric encryption. When you send an email to your friend and do not want anyone else to read it, you will need to secure that email. In order to make your email tamper-proof, you can use a public key to encrypt your email. This public key can be accessed by anyone and not just your friend whom you intend to send that secure email to. However, no one except your friend can access the contents of the email without the private key. Only the intended recipient, your friend, can access the private key and decrypt and access the email. This is how a S/MIME certificate works.

To sign and encrypt your email, you will need an email signing certificate – which you can purchase from a certificate authority. You can use this certificate to digitally sign your email. Once you purchase this certificate, it will get attached to your email automatically.

While the private key is used to generate the digital signature, the public key is used for authentication. The public and private keys are the two keys with which the digital signature is associated. The digital signature shows that the email sent is unaltered and not accessible to anyone else other than the intended recipient.

Features and Benefits of S/MIME Certificates

  • S/MIME certificates make sure the emails you send are accessible only by the recipient and not by any other third party.
  • These certificates use asymmetric encryption.
  • Public and private keys will be used to encrypt and decrypt emails so that you can be assured that the emails you send cannot be accessed by anyone else other than the recipient.
  • S/MIME certificates secure emails and make sure hackers do not access the contents of the email or make changes to it.
  • Digital signatures, as well as encryption, are both offered.
  • While asymmetric encryption lets you keep your data confidential, digital signatures offer authentication and message integrity.
  • S/MIME certificates are installed on email clients.

Uses of S/MIME

S/MIME can be used to

  • Make sure the email you sent has not been altered by any third party.
  • Create digital signatures to sign your emails.
  • Encrypt all your emails.
  • Verify the email client you use.

Document signing and client authentication are two of the additional features S/MIME certificates come with.

Document Signing

S/MIME certificates can be used for document signing, as well. Similar to email signing, you can sign documents using a digital signature. You can use your private key to sign your documents digitally. Using the unique digital signature, the recipient will be able to verify that the document was signed by you with your digital signature and that it has not been tampered.

If someone happens to tamper with the document you sent, the recipient will receive a warning message.

Client Authentication

Client authentication is another feature that S/MIME certificates offer. This feature helps users to secure apps, servers, and the network using certificate-based two-factor authentication. This feature will let you grant access to servers and apps to only authorized users. Only the users who have a client certificate installed will be able to access important data and the servers. Securing servers with passwords may not be a great option as passwords can be cracked. 

Having a S/MIME certificate with the client authentication feature is a great way to secure your servers and all-important data.

Final Word

The most popular form of electronic communication, emails, are largely used by businesses and individuals. It is also used by hackers for phishing purposes and to breach an organization’s network security. S/MIME certificates will prevent your emails from being tampered with. This is an important reason why you will need a S/MIME certificate to digitally sign your email and secure its contents so that no one other than the intended recipient can access it. Now that you know what a S/MIME certificate is and how it works, you might better understand the importance of these certificates for the security of your organization. Though S/MIME is implemented to strengthen email encryption, this technology can also help you stay away from social engineering attacks.

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What is RapidSSL SHA256 CA?

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Find out more about the Most Affordable Website Security worldwide

Hassle-free, High-end Security, and Cost-effectiveness are the three terms best-suited to define RapidSSL Domain Validated Certificates.

Established in 2003, RapidSSL is a leading certificate authority that specializes in issuing quality and cost-effective Domain Validated Certificates. For decades, RapidSSL has been exceeding expectations by offering faster and stronger levels of encryption – currently utilizing industry-standard SHA -256 (signature hash algorithm) for SSL certificates.

Who is Rapid SSL SHA 256 CA best suited for?

Rapid SSL SHA 256 CA best suited for individuals or small businesses, who require reliable and budget-friendly encryption to secure blogs, low-volume websites, testing domains, etc.,

RapidSSL CA provides two types of Certificates:

RapidSSL Standard and RapidSSL Wildcard

RapidSSL Standard is a Standard Domain Validated Certificate which is a basic but secure certificate, capable of securing a single domain or subdomain.

RapidSSL Wildcard, on the other hand, is a high-value certificate as it allows you to secure your website, as well as all your sub-domains.

Here is a brief comparison of the two:

RapidSSL Standard CertificateRapidSSL Wildcard Certificate
Validation LevelDomainDomain
SSL TypeSingle DomainDomain & All Subdomains
Warranty$ 10,000$ 10,000
IssuanceFew MinutesFew Minutes
Free Re-issuesYesYes
SSL CheckerYesYes
Encryption Strength256-bit256-bit
SHA 2YesYes
PeriodTwo yearsTwo years
Server LicensingUnlimitedUnlimited
Mobile Support99.99%99.99%
Browser Support99.99%99.99%
Site SealStaticStatic
Money Back Guarantee30-Days30-Days
24x7 SupportPhone, Web, Chat, E-mailPhone, Web, Chat, E-mail

Why choose RapidSSL?

Hassle-free, Super-fast Issuance:

Forget about Paper-work and getting on calls to prove your authenticity. Rapid SSL can easily issue certificates digitally within minutes, through a simple automated validation process that requires the customer to confirm the ownership of the respective Domain.


RapidSSL is an economical Certificate Authority known for its super-fast issuance and strong encryption levels. The reason that they are so affordable is that they are especially suited for Individuals and Small Enterprises to conduct basic transactions securely.

Unlimited Server Licenses & Free Re-issuance

RapidSSL Domain validated certificates provide an infinite number of server licenses at no extra cost. Moreover, during the SSL lifetime period, enjoy free unlimited RapidSSL Reissues.

Guarantee & Warranty:

At RapidSSL Customers are our most important priority. In case you are not satisfied with what you’ve got, RapidSSL provides a 30-day Money-back Guarantee on the product. Also, an additional $10,000 warranty is provided against any CA failure.

Customer Support:

RapidSSL provides round the clock customer support, with offerings such as Live Chat, E-mail, Telephone and Ticket Support.

Standard Encryption

RapidSSL uses SHA-256, a signature hash algorithm that generates a digital fingerprint to verify that information passed between the server and client was not tampered with. This method helps to protect confidential data and secure transactions.

Universally Supported:

RapidSSL Certificates are compatible with all modern desktop browsers and mobile devices.


  • Chrome
  • Firefox
  • Microsoft Edge
  • Internet Explorer
  • Opera
  • Safari

Server and Client OS

  • Control Panels: cPanel, Ensim, Citrix, DotNet Panel, Plesk, Hsphere, Helm, and more.
  • Web Servers: Apache, Microsoft IIS, IBM HTTP, Tomcat, Weblogic, Cobalt, etc.
  • E-Mail Servers: Lotus, Mail (Mac OS X & iOS), Exchange 2016, 2013 2010, 2007, Thunderbird, etc.
  • Client OS: Mac OS X, iOS, Android, Ubuntu, Windows Mobile, Chrome OS, Windows (all versions), etc.
  • Server OS: Linux, Windows Server (all versions), NGINX, UNIX, Solaris, Novell, Palm OS, etc.
  • Proxy Server, Routers & Firewalls: Microsoft ISA (all versions), CISCO, F5 Big-IP, Juniper, etc.

Mobile Browser

  • ACCESS NetFront
  • Atomic
  • Chrome
  • Dolphin HD
  • Fennec Alpha
  • Firefox
  • Internet Explorer (All Windows Devices)
  • Opera Mini
  • Opera Mobile
  • Openwave
  • Safari (iPhone, iPad, and iPod Touch)

Steps to install the Certificate

Step 1. Download the RapidSSL / Wildcard SHA-2 Intermediate CAs (under SHA-2 Root)
Step 2. Copy and paste the contents below (including the —–BEGIN CERTIFICATE—– and —–END CERTIFICATE—-) This CA bundle is applicable for the RapidSSL Certificate and RapidSSL Wildcard.

RSA SHA-2 (under SHA-2 Root) Intermediate CA


RSA SHA-2 (under SHA-2 Root) Root CA


Step 3. Activate the certificate

Please note that RapidSSL has a standard format of providing certificates; therefore, the installation process entirely depends on the control panel the client is using.

Alternatively, you can purchase the RapidSSL Installation Service (USD $29.99 for one certificate) which helps you by assigning a member of the team to install the certificate. Do note that in case of an extra server, an additional $25.00 is charged.

RapidSSL has grown to be an internationally trusted, and established Certificate Authority whose mission is to ensure the safety and security of manifold domains across the globe. Since RapidSSL is owned by DigiCert, one of the world’s largest digital certificate provider, authenticity and reliability does not even come into the question.

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How to Renew an SSL Certificate – The Ultimate Guide

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Step-by-step instructions on renewing your website’s SSL certificate.

It is necessary to renew SSL certificates regularly. Usually, SSL certificates need to be renewed or reissued every year. Shortly before the certificate expires, the user starts receiving notifications regarding its expiry. It’s necessary to renew SSL certificates before the expiration to prevent your website from being left unsecured.

Failure to renew SSL certificate in a timely manner will lead to the padlock sign or green address bar being removed from the website’s URL in the browser. Furthermore, Google will flash the “Not Secure” sign, which will deter other viewers from accessing the website, turning traffic away.

In this article, we’ll show you how to renew SSL certificates and answer some pertinent questions about SSL renewal.

How to Renew SSL Certificate And How to Renew Wildcard Certificate

Step 1: First, you must generate a new CSR. The only exception here is if you use an Apache server and if you haven’t changed your business details after purchasing your previous certificate.

Step 2: From your account, you need to select the Renew SSL link.

Step 3: Now select the specific SSL certificate you wish to renew.

Step 4: Your renewal request will be approved shortly. Following that, the certificate will be transferred to your registered email address.

Step 5: Backup the old certificate and then install and verify the new one. Be sure to uninstall the old certificate only after the new one has been verified so your site isn’t left without an SSL.

With these simple steps, you’ll have successfully renewed SSL certificate.

SSL Renewal FAQ

Can the expiration date of a certificate be extended?

All SSL certificates are hard-coded with the expiration date. As such, they cannot be changed. You simply have to “renew” the certificate — which essentially means getting a new certificate while using the same information used previously — and installing that.

When is it ideal to renew SSL certificate?

Users start receiving renewal reminders about 30 days prior to the certificate’s expiration. You should ideally renew the certificate any time before the certificate expires.

You won’t lose any time by renewing early–the certificate authority will add the unused time from your previous certificate to your new certificate.

What do I need to renew an SSL Certificate?

You will need a new CSR for the domain and your user name/password to access your account. If you don’t have username/password for your account, you can re-produce them from here.

Can I re-use my existing CSR or old CSR for SSL certificate renewal?

Some web servers will allow this, but we recommend a new CSR for every renewal.

Do I need to re-validate my company/organization details for EV SSL certificate renewal?

Yes, you need to re-validate your company/organization information If you are renewing an EV SSL certificate. However, in most cases the documents you previously supplied can be re-used for the validation process, so the process is often a lot quicker and easier.

Do I need to install the new SSL certificate after a complete renewal process?

Yes, you need to install the new certificate file on your web server. You cannot modify your previously installed certificate file – you have to install the new file.

If I renew before the expiration date, don’t I lose some of the time I paid for?

Nope! When renewing a certificate ahead of time, you’ll automatically get extra time added to your new certificate to make up for the “lost” time from your old certificate. In fact, you almost always get extra time, so it’s to your benefit to renew early.

As such, it’s beneficial to renew SSL certificates as soon as possible.


Renew SSL Certificates

Renew SSL Certificates of major SSL brands like RapidSSL, GeoTrust, Thawte, and Symantec. You can save up to 82% on renewal of SSL certificate.

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Top Trusted Certificate Authority/CA List Explained

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The Norton Secured Site seal is no longer offered starting Oct. 16, 2023.

Everything you needed to know about the top Certificate Authority/CA certificate in the industry

In this highly competitive market, there are a lot of certificate authorities vying for the users’ attention. In order to help you decide which are the most reliable and trustworthy, we’ve compiled a trusted certificate authority list.

Top 4 Trusted Certificate Authority List

In this certificate authority list, we’ll show you which certificates are the safest, most reasonable, and most reliable. Read on for a list of trusted certificate authorities.


DigiCert provides 2048-bit SSL certificates complete with a Norton Secured Seal on the website and priority support. They also provide a CertCentral® Management Platform that makes it easy for webmasters to guard their websites by automating and controlling every aspect of the certificate’s lifecycle. Furthermore, DigiCert provides certification to reputable sites like PayPal and Verizon as well.

Their StandardSSL Certificate starts at $188/yr and their advanced wildcard SSL Certificate starts at $625/yr.


RapidSSL certificates are reasonable and known for their quick service. They can be issued within a few minutes, are compatible with over 99% of all browsers, and they come insured with a $10,000 warranty.

A basic RapidSSL certificate starts at just $14.95/yr and an advanced Wildcard certificate costs $130/yr.


GeoTrust is the world’s second largest SSL provider with over 100,000 customers across 150 countries. Their certificates provide 256-bit SSL encryption and they come with a range of identifiable GeoTrust® True Site Seals that can indicate to users that your website is secure.

A basic QuickSSL Premium certificate is available for $68.50/yr and advanced Extended Validation and Wildcard certificates are available at $149/yr and $384/yr respectively.


Symantec is one of the most reputable names when it comes to SSL certification. Their website places special emphasis on security since they provide 256-bit encryption and a Norton Secured Seal, and all their certificates have a built-in Malware Scanning feature for added protection. They also have a reliable 24/7 customer support service.

Symantec offers a range of SSL/TLS certificates, from basic certificates like Secure Site and Secure Site with EV to advanced certificates like Secure Site Wildcard. However, their services are also considerably expensive, ranging from $279/yr to $1,999/yr. Symantec was purchased by DigiCert in 2017.


In short, the most trusted certificate authority list according to us is as follows:

  • DigiCert
  • RapidSSL
  • GeoTrust
  • Symantec

In this list of trusted certificate authorities, we’ve provided you with a detailed overview of these certificate authorities’ various features and differences. Now it’s up to you to decide which of these is most suitable for your SSL needs.

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SSL Comparison of Top Certificate Authorities: RapidSSL, Comodo, Godaddy, and GlobalSign

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The Perfect Guide to Tackle ERR_SSL_PROTOCOL_ERROR in Google Chrome

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ERR_SSL_PROTOCOL_ERROR in Google Chrome – Troubleshooting Guide

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Advanced Guide on Mac OS X Mavericks SSL Certificate Export and Import

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Step-by-step instructions for importing and exporting Mavericks SSL certificates

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Guide on How to View SSL Certificate in Chrome, Firefox, and Safari

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