What Is the File Extension CRT?

Secure Internet connections are important safety precautions necessary for the protection of sensitive information sent on websites. There are many file types associated with Internet security, including those that use the .crt extension.

Identification

A file with a .crt extension is known as a security certificate.

Function

A .crt file verifies that a website is secure and uses encryption to protect information transferred over it.

Use

A .crt file is saved on the server where a website is hosted. When you access a website that uses a secure connection, your computer looks for a certificate to authenticate the website, and once it is located, a lock appears at the top or bottom of your web browser.

Features

Websites purchase the security certificates contained in .crt files from services, such as Verisign and Thawte. The security certificate remains valid for a specific period of time, and once the certificate expires, users who visit the website may receive a message warning them the site cannot be authenticated as secure.

Considerations

Because these files are necessary for authentication, never delete a .crt file from a server.

References

• FileInfo.com: CRT File Extension