[Home](./index.md) > [puppeteer](./puppeteer.md) > [SecurityDetails](./puppeteer.securitydetails.md) > [protocol](./puppeteer.securitydetails.protocol.md)
## SecurityDetails.protocol() method
Signature:
```typescript
protocol(): string;
```
Returns:
string
The security protocol being used, e.g. "TLS 1.2".