How does SSL encryption work?

During the TLS handshake, the server presents its certificate, the client verifies it, both sides agree on cipher suites and exchange keys, and a secure session is established.

What types of SSL certificates exist?

Validation levels: DV (domain), OV (organization), EV (extended). Coverage: single-domain, wildcard (*.example.com), and multi‑domain (SAN).

DV vs OV vs EV — what’s the difference?

DV is quick and verifies domain control. OV verifies business identity as well. EV involves the most rigorous checks and offers the highest assurance. Modern browsers no longer show a green bar for EV.

How do I renew an SSL certificate?

Track expiration, generate a new CSR, submit renewal to your CA, complete validation, install the renewed certificate, and test for mixed content and redirects.

Is SSL the same as TLS?

TLS is the modern successor to SSL. The industry colloquially says ‘SSL’, but current secure connections use TLS 1.2 or TLS 1.3.

SSL Certificate FAQ: Types, Installation, Errors, Renewals

Q: What is an SSL certificate?

An SSL (Secure Sockets Layer) certificate — more accurately TLS today — authenticates your website and enables encrypted connections between browser and server.

Q: Why do I need an SSL certificate?

SSL/TLS protects data in transit, builds user trust, prevents browser warnings, can improve SEO, and is required for payments and many compliance standards.

Q: How do I install an SSL certificate?

Apache: configure vhost with certificate, key, and chain. Nginx: set ssl_certificate and ssl_certificate_key. IIS: import PFX and bind to the site. Always include intermediates and force HTTPS.

Q: How long does issuance take?

DV: minutes to hours. OV: 1–3 business days. EV: 1–5 business days depending on verification responsiveness.

Q: Why is my SSL certificate invalid?

Common causes: expired cert, hostname mismatch, missing intermediate chain, server misconfiguration, or mixed content (HTTP assets on HTTPS pages).

What is an SSL certificate?

An SSL (Secure Sockets Layer) certificate authenticates your website and enables encrypted connections between browser and server.

Protects sensitive data
Builds visitor trust
Improves SEO rankings
Helps with compliance

Why do I need an SSL certificate?

Security: Encrypts data in transit
Trust: Modern browsers highlight HTTPS
SEO: HTTPS preferred in search
Compliance: Required for payments

How does SSL/TLS encryption work?

Client Hello
Server Hello + Certificate
Certificate verification
Key exchange
Encrypted communication

What are the different types of SSL certificates?

By validation:

DV – domain only
OV – business verified
EV – highest assurance

By coverage:

Single-domain
Wildcard (*.example.com)
Multi-domain (SAN)

What’s the difference between DV, OV and EV?

DV: Fast, low cost, padlock only
OV: Company verification, higher trust
EV: Rigorous checks, maximum trust

How do I install an SSL certificate?

Varies by server:

Apache: configure vhost with cert, key, chain
Nginx: add ssl_certificate, ssl_certificate_key
IIS: import PFX and bind to site

How long does issuance take?

DV: minutes to hours
OV: 1–3 business days
EV: 1–5 business days

Why is my SSL certificate invalid?

Expired certificate
Hostname mismatch
Missing intermediate chain
Server misconfiguration
Mixed content

Use our SSL Checker to diagnose.

How do I renew my SSL certificate?

Check expiration and generate a new CSR
Submit renewal to your CA
Complete validation and install
Test with SSL tools

For automated renewal, consider using Let's Encrypt with Certbot.

How can I automate SSL certificate renewals?

Several methods for automation:

Let's Encrypt + Certbot: Free automated certificates
ACME Protocol: Standard for automated certificate management
Monitoring Tools: Set up alerts for expiry dates
CI/CD Integration: Include certificate renewal in deployment pipelines

Read our comprehensive automation guide for detailed implementation.

Does SSL affect website performance?

SSL adds minimal overhead with proper optimization:

Initial Handshake: 50-200ms additional latency
CPU Usage: 1-5% increase for encryption/decryption
Bandwidth: Minimal increase due to encryption

Optimization techniques include HTTP/2, session resumption, and OCSP stapling. See our performance optimization guide.

What are the latest SSL security best practices?

TLS 1.2+: Use modern protocol versions
Strong Cipher Suites: AES-GCM, ChaCha20-Poly1305
HSTS: HTTP Strict Transport Security
Certificate Transparency: Monitor certificate issuance
Regular Updates: Keep server software current

Follow our security audit guide for comprehensive assessment.

How do I manage SSL certificates in an enterprise environment?

Enterprise SSL management requires:

Certificate Inventory: Track all certificates across environments
Lifecycle Management: Automated renewal and deployment
Compliance Monitoring: Ensure policy adherence
Centralized Platform: Use enterprise certificate management tools

Learn more in our enterprise management guide.

What should I do if my SSL certificate shows as "Not Secure"?

Common causes and solutions:

Mixed Content: HTTP resources on HTTPS pages
Certificate Chain Issues: Missing intermediate certificates
Expired Certificate: Renew immediately
Self-signed Certificate: Replace with trusted CA certificate

Use our SSL Checker to diagnose specific issues.

What SSL requirements exist for compliance standards?

Key compliance requirements:

PCI DSS: Strong cryptography, regular testing
HIPAA: Data encryption in transit
SOX: Internal controls and documentation
GDPR: Data protection by design

Ensure your SSL implementation meets relevant compliance standards for your industry.

How do I fix SSL handshake errors?

Common handshake error solutions:

Protocol Mismatch: Ensure client and server support compatible TLS versions
Cipher Suite Issues: Configure compatible cipher suites
Certificate Problems: Verify certificate validity and chain
Network Issues: Check firewall and proxy settings

See our troubleshooting guide for detailed solutions.

Can I use wildcard certificates for multiple subdomains?

Yes, wildcard certificates support unlimited subdomains:

Format: *.example.com covers all subdomains
Limitations: Only covers one level of subdomains
Security: Higher risk if private key is compromised
Cost: More expensive than single-domain certificates

Consider SAN certificates for multiple specific domains.

What is HTTP/2 and how does it work with SSL?

HTTP/2 provides significant performance benefits:

Multiplexing: Multiple requests over single connection
Server Push: Proactive resource delivery
Header Compression: Reduced overhead with HPACK
Binary Protocol: More efficient than HTTP/1.1

Most browsers require HTTPS for HTTP/2, making SSL essential for modern web performance.