What are certificates used for?

Server or SSL Certificates perform a very similar role to Client Certificates, except the latter is used to identify the client/individual and the former authenticates the owner of the site. Server certificates typically are issued to hostnames, which could be a machine name (such as ‘XYZ-SERVER-01’) or domain name (such as ‘www.digicert.com’). A web browser reaching the server, and validates that an SSL server certificate is authentic. That tells the user that their interaction with the web site has no eavesdroppers and that the web site is exactly who it claims to be. This security is critical for electronic commerce, which is why certificates are now in such widespread use.

How do they do that? In practice, a web site operator obtains a certificate by applying to a certificate provider with a certificate signing request. This is an electronic document that contains all the essential information: web site name, contact email address and company information. The certificate provider signs the request, producing a public certificate, which is served to any web browser that connects to the web site and, crucially, proves to the web browser that the provider issued a certificate to the person he believes to be the owner of the web site. Before issuing a certificate, however, the certificate provider will request the contact email address for the web site from a public domain name registrar and check that published address against the email address supplied in the certificate request, ensuring the circle of trust has been closed.

Moreover, you can configure a web site so that any user wishing to connect is required to provide a valid client certificate, and valid user name and password. This is usually referred to as ‘two-factor authentication’ – in this instance, ’something you know’ (password) and ’something you have’ (certificate).

For those engaged in transactions on the web, certificates mean an end to anonymity and instead provide assurance that this is someone you can trust; that they are who they say they are. In an online world where our safety is being challenged constantly, such reassurance is invaluable.

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Encryption is a mathematical process of coding and decoding information. The number of bits (40-bit, 56-bit, 128-bit, 256-bit) tells you the size of the key. Like a longer password, a larger key has more possible combinations. In fact, 128-bit encryption is one trillion times stronger than 40-bit encryption. When an encrypted session is established, the strength is determined by the capability of the web browser, SSL certificate, web server, and client computer operating system.

SSL Certificates are small data files that digitally bind a cryptographic key to an organization’s details. When installed on a web server, it activates the padlock and the https protocol and allows secure connections from a web server to a browser. Typically, SSL is used to secure credit card transactions, data transfer and logins, and more recently is becoming the norm when securing browsing of social media sites.

SSL Certificates bind together:

• A domain name, server name or hostname.
• An organizational identity (i.e. company name) and location.

Note: As of August 2020 most browsers will no longer display the green padlock and address bar to indicate Extended Validation.

An organization needs to install the SSL Certificate onto its web server to initiate a secure session with browsers. Once a secure connection is established, all web traffic between the web server and the web browser will be secure.

When a certificate is successfully installed on your server, the application protocol (also known as HTTP) will change to HTTPS, where the ‘S’ stands for ‘secure’.

What are the different types of SSL certificates?

How Does an SSL Certificate Work?

SSL Certificates use something called public key cryptography.

This particular kind of cryptography harnesses the power of two keys which are long strings of randomly generated numbers. One is called a private key and one is called a public key. A public key is known to your server and available in the public domain. It can be used to encrypt any message. If Alice is sending a message to Bob she will lock it with Bob’s public key but the only way it can be decrypted is to unlock it with Bob’s private key. Bob is the only one who has his private key so Bob is the only one who can use this to unlock Alice’s message. If a hacker intercepts the message before Bob unlocks it, all they will get is a cryptographic code that they cannot break, even with the power of a computer.

If we look at this in terms of a website, the communication is happening between a website and a server. Your website and server are Alice and Bob.

Why Do I Need an SSL Certificate?

SSL Certificates protect your sensitive information such as credit card information, usernames, passwords etc. They also:

• Keep data secure between servers
• Increase your Google Rankings
• Build/Enhance customer trust
• Improve conversion rates

Where Do I Buy an SSL Certificate?

SSL Certificates need to be issued from a trusted Certificate Authority (CA). Browsers, operating systems, and mobile devices maintain lists of trusted CA root certificates.

The Root Certificate must be present on the end user's machine in order for the Certificate to be trusted. If it is not trusted the browser will present untrusted error messages to the end user. In the case of e-commerce, such error messages result in immediate lack of confidence in the website and organizations risk losing confidence and business from consumers.

Companies like GlobalSign are known as trusted Certificate Authorities. This is because browser and operating system vendors such as Microsoft, Mozilla, Opera, Blackberry, Java, etc., trust that GlobalSign is a legitimate Certificate Authority and that it can be relied on to issue trustworthy SSL Certificates. The more applications, devices and browsers the Certificate Authority embeds its Root into, the better "recognition" the SSL Certificate can provide.

GlobalSign was founded in 1996 in Europe and remains one of the longest running Certificate Authorities in the region.

Compare SSL Certificates and Pricing

An SSL certificate is a digital certificate that authenticates a website's identity and enables an encrypted connection. SSL stands for Secure Sockets Layer, a security protocol that creates an encrypted link between a web server and a web browser.

Companies and organizations need to add SSL certificates to their websites to secure online transactions and keep customer information private and secure.

In short: SSL keeps internet connections secure and prevents criminals from reading or modifying information transferred between two systems. When you see a padlock icon next to the URL in the address bar, that means SSL protects the website you are visiting.

Since its inception about 25 years ago, there have been several versions of SSL protocol, all of which at some point ran into security troubles. A revamped and renamed version followed — TLS (Transport Layer Security), which is still in use today. However, the initials SSL stuck, so the new version of the protocol is still usually called by the old name.

How do SSL certificates work?

SSL works by ensuring that any data transferred between users and websites, or between two systems, remains impossible to read. It uses encryption algorithms to scramble data in transit, which prevents hackers from reading it as it is sent over the connection. This data includes potentially sensitive information such as names, addresses, credit card numbers, or other financial details.

The process works like this:

1. A browser or server attempts to connect to a website (i.e., a web server) secured with SSL.
2. The browser or server requests that the web server identifies itself.
3. The web server sends the browser or server a copy of its SSL certificate in response.
4. The browser or server checks to see whether it trusts the SSL certificate. If it does, it signals this to the webserver.
5. The web server then returns a digitally signed acknowledgment to start an SSL encrypted session.
6. Encrypted data is shared between the browser or server and the webserver.

This process is sometimes referred to as an "SSL handshake." While it sounds like a lengthy process, it takes place in milliseconds.

When a website is secured by an SSL certificate, the acronym HTTPS (which stands for HyperText Transfer Protocol Secure) appears in the URL. Without an SSL certificate, only the letters HTTP – i.e., without the S for Secure – will appear. A padlock icon will also display in the URL address bar. This signals trust and provides reassurance to those visiting the website.

To view an SSL certificate's details, you can click on the padlock symbol located within the browser bar. Details typically included within SSL certificates include:

• The domain name that the certificate was issued for
• Which person, organization, or device it was issued to
• Which Certificate Authority issued it
• The Certificate Authority's digital signature
• Associated subdomains
• Issue date of the certificate
• The expiry date of the certificate
• The public key (the private key is not revealed)

Why you need an SSL certificate

Websites need SSL certificates to keep user data secure, verify ownership of the website, prevent attackers from creating a fake version of the site, and convey trust to users.

If a website is asking users to sign in, enter personal details such as their credit card numbers, or view confidential information such as health benefits or financial information, then it is essential to keep the data confidential. SSL certificates help keep online interactions private and assure users that the website is authentic and safe to share private information with.

More relevant to businesses is the fact that an SSL certificate is required for an HTTPS web address. HTTPS is the secure form of HTTP, which means that HTTPS websites have their traffic encrypted by SSL. Most browsers tag HTTP sites – those without SSL certificates – as "not secure." This sends a clear signal to users that the site may not be trustworthy – incentivizing businesses who have not done so to migrate to HTTPS.

An SSL certificate helps to secure information such as:

• Login credentials
• Credit card transactions or bank account information
• Personally identifiable information — such as full name, address, date of birth, or telephone number
• Legal documents and contracts
• Medical records
• Proprietary information

Types of SSL certificate

There are different types of SSL certificates with different validation levels. The six main types are:

1. Extended Validation certificates (EV SSL)
2. Organization Validated certificates (OV SSL)
3. Domain Validated certificates (DV SSL)
4. Wildcard SSL certificates
5. Multi-Domain SSL certificates (MDC)
6. Unified Communications Certificates (UCC)

Extended Validation certificates (EV SSL)

This is the highest-ranking and most expensive type of SSL certificate. It tends to be used for high profile websites which collect data and involve online payments. When installed, this SSL certificate displays the padlock, HTTPS, name of the business, and the country on the browser address bar. Displaying the website owner's information in the address bar helps distinguish the site from malicious sites. To set up an EV SSL certificate, the website owner must go through a standardized identity verification process to confirm they are authorized legally to the exclusive rights to the domain.

Organization Validated certificates (OV SSL)

This version of SSL certificate has a similar assurance similar level to the EV SSL certificate since to obtain one; the website owner needs to complete a substantial validation process. This type of certificate also displays the website owner's information in the address bar to distinguish from malicious sites. OV SSL certificates tend to be the second most expensive (after EV SSLs), and their primary purpose is to encrypt the user's sensitive information during transactions. Commercial or public-facing websites must install an OV SSL certificate to ensure that any customer information shared remains confidential.

Domain Validated certificates (DV SSL)

The validation process to obtain this SSL certificate type is minimal, and as a result, Domain Validation SSL certificates provide lower assurance and minimal encryption. They tend to be used for blogs or informational websites – i.e., which do not involve data collection or online payments. This SSL certificate type is one of the least expensive and quickest to obtain. The validation process only requires website owners to prove domain ownership by responding to an email or phone call. The browser address bar only displays HTTPS and a padlock with no business name displayed.

Wildcard SSL certificates

Wildcard SSL certificates allow you to secure a base domain and unlimited sub-domains on a single certificate. If you have multiple sub-domains to secure, then a Wildcard SSL certificate purchase is much less expensive than buying individual SSL certificates for each of them. Wildcard SSL certificates have an asterisk * as part of the common name, where the asterisk represents any valid sub-domains that have the same base domain. For example, a single Wildcard certificate for *website can be used to secure:

• payments.yourdomain.com
• login.yourdomain.com
• mail.yourdomain.com
• download.yourdomain.com
• anything.yourdomain.com

Multi-Domain SSL Certificate (MDC)

A Multi-Domain certificate can be used to secure many domains and/or sub-domain names. This includes the combination of completely unique domains and sub-domains with different TLDs (Top-Level Domains) except for local/internal ones.

For example:

• www.example.com
• example.org
• mail.this-domain.net
• example.anything.com.au
• checkout.example.com
• secure.example.org

Multi-Domain certificates do not support sub-domains by default. If you need to secure both www.example.com and example.com with one Multi-Domain certificate, then both hostnames should be specified when obtaining the certificate.

Unified Communications Certificate (UCC)

Unified Communications Certificates (UCC) are also considered Multi-Domain SSL certificates. UCCs were initially designed to secure Microsoft Exchange and Live Communications servers. Today, any website owner can use these certificates to allow multiple domain names to be secured on a single certificate. UCC Certificates are organizationally validated and display a padlock on a browser. UCCs can be used as EV SSL certificates to give website visitors the highest assurance through the green address bar.

It is essential to be familiar with the different types of SSL certificates to obtain the right type of certificate for your website.

How to obtain an SSL certificate

SSL certificates can be obtained directly from a Certificate Authority (CA). Certificate Authorities – sometimes also referred to as Certification Authorities – issue millions of SSL certificates each year. They play a critical role in how the internet operates and how transparent, trusted interactions can occur online.

The cost of an SSL certificate can range from free to hundreds of dollars, depending on the level of security you require. Once you decide on the type of certificate you require, you can then look for Certificate Issuers, which offer SSLs at the level you require.

Obtaining your SSL involves the following steps:

• Prepare by getting your server set up and ensuring your WHOIS record is updated and matches what you are submitting to the Certificate Authority (it needs to show the correct company name and address, etc.)
• Generating a Certificate Signing Request (CSR) on your server. This is an action your hosting company can assist with.
• Submitting this to the Certificate Authority to validate your domain and company details
• Installing the certificate they provide once the process is complete.

Once obtained, you need to configure the certificate on your web host or on your own servers if you host the website yourself.

How quickly you receive your certificate depends on what type of certificate you get and which certificate provider you procure it from. Each level of validation takes a different length of time to complete. A simple Domain Validation SSL certificate can be issued within minutes of being ordered, whereas Extended Validation can take as long as a full week.

Can an SSL certificate be used on multiple servers?

It is possible to use one SSL certificate for multiple domains on the same server. Depending on the vendor, you can also use one SSL certificate on multiple servers. This is because of Multi-Domain SSL certificates, which we discussed above.

As the name implies, Multi-Domain SSL Certificates work with multiple domains. The number is left up to the specific issuing Certificate Authority. A Multi-Domain SSL Certificate is different from a Single Domain SSL Certificate, which – again, as the name implies – is designed to secure a single domain.

To make matters confusing, you may hear Multi-Domain SSL Certificates, also referred to as SAN certificates. SAN stands for Subject Alternative Name. Every multi-domain certificate has additional fields (i.e., SANs), which you can use to list additional domains that you want to cover under one certificate.

Unified Communications Certificates (UCCs) and Wildcard SSL Certificates also allow for multi-domains and, in the latter case, an unlimited number of subdomains.

What happens when an SSL certificate expires?

SSL certificates do expire; they don't last forever. The Certificate Authority/Browser Forum, which serves as the de facto regulatory body for the SSL industry, states that SSL certificates should have a lifespan of no more than 27 months. This essentially means two years plus you can carry over up to three months if you renew with time remaining on your previous SSL certificate.

SSL certificates expire because, as with any form of authentication, information needs to be periodically re-validated to check it is still accurate. Things change on the internet, as companies and also websites are bought and sold. As they change hands, the information relevant to SSL certificates also changes. The purpose of the expiry period is to ensure that the information used to authenticate servers and organizations is as up-to-date and accurate as possible.

Previously, SSL certificates could be issued for as long as five years, which was subsequently reduced to three and most recently to two years plus a potential extra three months. In 2020, Google, Apple, and Mozilla announced they would enforce one-year SSL certificates, despite this proposal being voted down by the Certificate Authority Browser Forum. This took effect from September 2020. It is possible that in the future, the length of validity will reduce still further.

When an SSL certificate expires, it makes the site in question unreachable. When a user's browser arrives at a website, it checks the SSL certificate's validity within milliseconds (as part of the SSL handshake). If the SSL certificate has expired, visitors will receive a message to the effect of — "This site is not secure. Potential risk ahead".

While users do have the option to proceed, it is not advisable to do so, given the cybersecurity risks involved, including the possibility of malware. This will significantly impact bounce rates for website owners, as users rapidly click off the homepage and go elsewhere.

Keeping on top of when SSL certificates expire presents a challenge for larger businesses. While smaller and medium-sized businesses (SMEs) may have one or only a few certificates to manage, enterprise-level organizations that potentially transact across markets – with numerous websites and networks – will have many more. At this level, allowing an SSL certificate to expire is usually the result of oversight rather than incompetence. The best way for larger businesses to stay on top of when their SSL certificates expire is by using a certificate management platform. There are various products on the market, which you can find using an online search. These allow enterprises to see and manage digital certificates across their entire infrastructure. If you do use one of these platforms, it is important to log in regularly so you can be aware of when renewals are due.

If you allow a certificate to expire, the certificate becomes invalid, and you will no longer be able to run secure transactions on your website. The Certification Authority (CA) will prompt you to renew your SSL certificate before the expiration date.

Whichever Certificate Authority or SSL service you use to obtain your SSL certificates from will send you expiration notifications at set intervals, usually starting at 90 days out. Try to ensure that these reminders are being sent to an email distribution list — rather than a single individual, who may have left the company or moved to another role by the time the reminder is sent. Think about which stakeholders in your company are on this distribution list to ensure the right people see the reminders at the right time.

How to tell if a site has an SSL certificate

The easiest way to see if a site has an SSL certificate is by looking at the address bar in your browser:

• If the URL begins with HTTPS instead of HTTP, that means the site is secured using an SSL certificate.
• Secure sites show a closed padlock emblem, which you can click on to see security details – the most trustworthy sites will have green padlocks or address bars.
• Browsers also show warning signs when a connection is not secure — such as a red padlock, a padlock which is not closed, a line going through the website's address, or a warning triangle on top of the padlock emblem.

How to ensure your online session is safe

Only submit your personal data and online payment details to websites with EV or OV certificates. DV certificates are not suitable for eCommerce websites. You can tell if a site has an EV or OV certificate by looking at the address bar. For an EV SSL, the organization's name will be visible in the address bar itself. For an OV SSL, you can see the organization's name's details by clicking on the padlock icon. For a DV SSL, only the padlock icon is visible.

Read the website's privacy policy. This enables you to see how your data will be used. Legitimate companies will be transparent about how they collect your data and what they do with it.

Look out for trust signals or indicators on websites.
As well as SSL certificates, these include reputable logos or badges which show the website meets specific security standards. Other signs that can help you determine if a site is real or not include checking for a physical address and telephone number, checking their returns or refunds policy, and making sure prices are believable and not too good to be true.

Stay alert to phishing scams.
Sometimes cyber attackers create websites that mimic existing websites to trick people into purchasing something or logging in to their phishing site. It is possible for a phishing site to obtain an SSL certificate and therefore encrypt all the traffic that flows between you and it. A growing proportion of phishing scams occur on HTTPS sites — deceiving users who feel reassured by the padlock icon's presence.

To avoid these kinds of attacks:

• Always examine the domain of the site you are on and ensure it is spelled correctly. The URL of a fake site might differ by only one character – e.g., amaz0n.com instead of amazon.com. If in doubt, type the domain directly into your browser to make sure you are connecting to the website you intend to visit.
• Never enter logins, passwords, banking credentials, or any other personal information on the site unless you are sure of its authenticity.
• Always consider what a particular site is offering, whether it looks suspicious, and whether you really need to register on it.
• Make sure your devices are well protected: Kaspersky Internet Security checks URLs against an extensive database of phishing sites, and it detects scams regardless of how "safe" the resource looks.

Cybersecurity risks continue to evolve but understanding the types of SSL certificates to look out for and how to distinguish a safe site from a potentially dangerous one will help internet users avoid scams and protect their personal data from cybercriminals.

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