<!-- Do not edit this file. It is automatically generated by API Documenter. --> [Home](./index.md) > [puppeteer](./puppeteer.md) > [SecurityDetails](./puppeteer.securitydetails.md) > [protocol](./puppeteer.securitydetails.protocol.md) ## SecurityDetails.protocol() method <b>Signature:</b> ```typescript protocol(): string; ``` <b>Returns:</b> string The security protocol being used, e.g. "TLS 1.2".