Let’s Encrypt

Let’s Encrypt is a nonprofit certificate authority that provides free digital certificates to enable HTTPS on websites. Its main goal is to make encrypted connections the standard across the web. By offering domain-validated SSL/TLS certificates at no cost, and by automating the issuance and renewal process, Let’s Encrypt has changed how website owners secure their traffic. It helps make secure web browsing more accessible to small websites, developers, and large hosting providers alike.

Let’s Encrypt is operated by the Internet Security Research Group (ISRG). Its service is trusted by all major browsers and platforms.

History

Let’s Encrypt launched publicly in December 2015 after nearly two years of planning and development. The goal was to make secure web connections a default feature—free, automatic, and accessible to everyone. At the time, obtaining an SSL certificate had several hurdles:

• SSLs required payment
• There were several validation steps
• SSLs require periodic renewal.

This created a barrier for smaller websites, hobby projects, and developers with limited resources.

Before Let’s Encrypt, the certificate authority market was dominated by a few commercial providers. Costs ranged from tens to hundreds of dollars per year, depending on the certificate type. Adoption of HTTPS was slow as a result.

To solve these issues, the Internet Security Research Group partnered with Mozilla, the Electronic Frontier Foundation (EFF), Cisco, Akamai, and others. Together, they designed a system that would:

• Issue certificates for free
• Automate domain verification, installation, and renewal
• Require no manual involvement after initial setup
• Rely on open standards and open-source software

They created the Automatic Certificate Management Environment (ACME) protocol to handle these tasks. ACME later became a widely adopted standard for automated certificate issuance.

• In late 2015, Let’s Encrypt issued its first certificate
• By mid-2017, it had become one of the world’s largest certificate authorities
• As of today, it issues hundreds of millions of certificates
• It’s widely integrated with web servers, hosting panels, and operating systems

Let’s Encrypt helped shift the web toward default encryption, turning HTTPS from a costly feature into a baseline expectation.

How It Works

Let’s Encrypt issues domain-validated certificates. This means the certificate confirms that the person requesting it controls the domain. It does not verify identity or business details. The process relies on the ACME protocol.

To get a certificate, a client (usually software running on the server) sends a request to the Let’s Encrypt service. The service then asks the client to prove domain control. There are two main ways to do this:

• HTTP challenge: The client places a specific file at a known path on the website. Let’s Encrypt checks this file over HTTP to confirm control.
• DNS challenge: The client adds a DNS TXT record with a specific value. Let’s Encrypt checks the DNS entry to confirm control.

Once validation is successful, Let’s Encrypt issues the certificate. The client can then install it on the server.

Certificates are valid for 90 days. The short lifetime encourages automation. Most users run a scheduled job to renew the certificate automatically before it expires.

ACME Clients

Many software tools support the ACME protocol. The most well-known is Certbot, maintained by the EFF. It can install and renew certificates on many platforms, including Apache, NGINX, and HAProxy.

Other clients include:

• acme.sh – a lightweight shell script with wide compatibility
• lego – a Go-based client often used in container environments
• Caddy – a web server with built-in HTTPS using Let’s Encrypt
• Hepsia, cPanel, and DirectAdmin – control panels that integrate Let’s Encrypt into their interfaces

Most hosting environments now include Let’s Encrypt support out of the box. When a user creates a new domain, the system can request a certificate and install it with no manual steps

Key Features

Let’s Encrypt certificates use RSA or ECDSA public key algorithms. All certificates follow modern security practices and chain to a trusted root recognized by browsers and devices.

Key features include:

• No cost: Certificates are free to issue and renew.
• Automatic issuance: ACME protocol handles validation and download.
• Automatic renewal: Short lifetimes and scheduling tools prevent expiry.
• Open infrastructure: Source code and standards are public.
• Wide trust: All major browsers and operating systems recognize Let’s Encrypt.

Let’s Encrypt only issues domain-validated certificates. It does not offer Organization Validation (OV) or Extended Validation (EV), which involve manual checks of business identity.

Impact on the Web

Let’s Encrypt changed the security landscape by lowering the barriers to HTTPS adoption. Before it launched, many websites remained on HTTP because of cost or complexity. Within a few years of its release, HTTPS usage grew sharply. Major browser vendors helped drive this trend by warning users about insecure sites and prioritizing secure content.

Hosting companies began offering HTTPS as a default feature, using Let’s Encrypt to power their backends. For many users, HTTPS became automatic. Free certificates also made it easier for open-source platforms and small projects to protect their users.

Today, more than 90 percent of all page loads in many regions use HTTPS. Much of that growth is linked to Let’s Encrypt and the ACME ecosystem.

Advantages

• Free and Widely Trusted - Let’s Encrypt certificates are completely free. This removes the cost barrier for individuals, startups, and nonprofits. Certificates are trusted by all major browsers, meaning no warning messages for users.
• Easy to Automate - ACME clients like Certbot can handle issuance, installation, and renewal with no human input. This reduces errors and prevents expiry-related downtime.
• Rapid Deployment - Setup takes minutes on most platforms. Control panels and server software often include built-in support, removing the need to install tools manually.
• Privacy-Focused - Let’s Encrypt supports HTTPS for all users without collecting personal data. It avoids email verification and uses automated domain control checks instead.
• Open Standards - The service helped create the ACME protocol, which is now a public IETF standard. Its tools and infrastructure are open-source, allowing others to build on the model.
• Community Support - Let’s Encrypt has a large community of users, developers, and contributors. Public forums, documentation, and third-party guides make support easy to find.

Limitations

• Domain Validation Only - Let’s Encrypt certificates confirm domain control but not business identity. For ecommerce sites that want to show their verified organization name, paid EV certificates are still needed.
• Short Validity - Certificates last for 90 days. While this encourages automation, it requires extra setup. Servers without proper renewal scripts risk letting certificates expire.
• No Wildcard Support via HTTP - Wildcard certificates require DNS validation. This can be harder to automate, especially for users who cannot modify DNS records via API.
• No Custom Certificate Features - Let’s Encrypt does not support special certificate configurations or features like multi-year validity or special SAN configurations.
• Rate Limits - Let’s Encrypt has limits on how many certificates can be issued per domain per week. Most users never hit these limits, but large platforms must manage issuance carefully.

Let’s Encrypt vs. Commercial CAs

Commercial certificate authorities offer a range of options beyond what Let’s Encrypt provides. These include OV and EV validation, extended lifetimes, warranties, and custom branding. Businesses that need strong identity validation or specific contract terms may still choose commercial options.

Let’s Encrypt focuses on basic security: encrypting data in transit. It does not claim to verify identity or protect from phishing. Its goal is to make HTTPS the default, not to replace all types of certificates.

For most general websites, blogs, APIs, and even small businesses, Let’s Encrypt provides all the technical benefits of HTTPS without the cost.

NTC Hosting and Let’s Encrypt

Let’s Encrypt SSL Certificates provide essential encryption for websites, ensuring secure data transmission between users and servers. These certificates are widely recognized for their ease of use and reliability, making them a popular choice for enhancing website security.

NTC Hosting offers Let’s Encrypt SSL Certificates for free through the Hepsia Control Panel, available across all hosting services - web hosting, VPS, semi-dedicated servers, and dedicated servers. This integration allows users to easily secure their websites with trusted SSL encryption, improving security and boosting visitor trust without any additional cost.