What are SSL Certificates?

SSL (Secure Sockets Layer) certificates are digital certificates that establish an encrypted link between a server and a browser. They allow sensitive data like credit card details, login credentials, personal messages etc. to be transmitted securely over the internet. SSL certificates use public-key cryptography to encrypt data being transmitted between the server and client. When you access a website via https:// instead of http://, it means the site has SSL encryption enabled via an SSL certificate.

 

How do SSL Certificates Work?

 

SSL certificates work on the concept of public-key cryptography. During the SSL handshake, the server with an SSL certificate sends its public key to the connecting client and browser. The browser uses this public key to encrypt a symmetric session key which it sends back to the server. Only the server can decrypt this message using its private key. From then on, this session key is used to encrypt all communication between the server and client for the duration of their session. Even if someone intercepts this encrypted data traffic, they won't be able to decrypt it without the session key.

 

Types of SSL Certificates

 

There are different types of SSL certificates available depending on the intended usage:

 

Domain Validated (DV): These are the basic and most affordable SSL certificates. They only validate that the certificate owner controls the domain.

 

Organization Validated (OV): OV certificates provide stronger validation that the organization exists. They require more documentation to prove business ownership and legal existence.

 

Extended Validation (EV): EV SSL is the most rigorous validation standard, requiring extensive documentation review and legal approval. EV SSL displays company details in the browser URL bar for higher trust levels.

 

Wildcard Certificates: Wildcard SSL certificates secure an entire domain like *.example.com instead of a single subdomain. They cover an unlimited number of subdomains on a single domain.

 

Unified Communications (UC): UC certificates are meant for VOIP, video conferencing and other real-time communication apps over HTTPS.

 

Multiple Domain (SAN): Subject Alternative Name (SAN) certificates allow securing multiple fully-qualified domain names on a single certificate.

 

Private SSL Certificates: Private certificates are issued privately by a Certificate Authority instead of being publicly trusted. They are used internally within private company networks.

 

Benefits of SSL Certificates for Websites

 

SSL certification offers numerous security and user experience benefits for websites:

 

Encrypts Data in Transit: Ensures all data transmitted between the server and user's browser remains encrypted and immune to eavesdropping or tampering.

 

Browser Trust Indicators: The green lock and https:// in the URL bar signal users that the site can be trusted with sensitive data submissions.

 

Protects User Credentials: Stops potential man-in-the-middle attackers from intercepting usernames, passwords and other private credentials.

 

Prevents Phishing & Spoofing: SSL helps verify genuine domain ownership and prevents domains from spoofing legitimate sites.

 

SEO Advantage: Search engines give https:// sites a ranking boost for being more secure user experiences.

 

Retains Conversion Rates: Users feel safer sharing data on sites protected by SSL, improving conversions and transactions.

 

Compliance Requirements: Some regulations and standards like PCI DSS mandate SSL protection for handling sensitive customer data.

 

Factors to Consider When Choosing an SSL Certificate

 

When selecting the right SSL certificate for your needs, consider factors like:

 

Certificate Type: DV, OV or EV based on validation requirements and desired trust levels.

 

Domain Names: Single domain, multiple subdomains, wildcard or SAN for multiple fully-qualified names.

 

Key Type & Size: RSA or ECDSA keys with recommended minimum 2048-bit key strength.

 

Expiry Period: 1, 2 or 3-year validity durations depending on budget and renewal planning.

 

Issuer Authority: Choose providers like Symantec, GeoTrust, DigiCert etc. for wide browser recognition.

 

Compatibility: Check provider support for all intended platforms, browsers and devices.

 

Advanced Features: Options like free reissues, multi-domain, auto-renewal etc.

 

Pricing: Upfront cost, any setup fees, possible discounts for multi-year subscriptions.

 

Overall, SSL Certificates provide an important layer of security, trust and user confidence for websites. Properly implemented SSL protects sensitive data in transit and maintains compliance. With so many certificate options available, selecting the right one requires considering key technical and business factors.