Password Protection
Password-protect your surveys when you want to share them with specific groups. Anyone trying to access the survey will be shown a popup asking for the password before they can proceed.
![Password protection](http://www.zohowebstatic.com/sites/zweb/images/survey/features/pswdprotection.png)
Prevent Multiple Responses
Make sure that people can only submit a single set of responses to your survey. You can use cookies or provide a unique URL to ensure that each respondent can only access it once.
![](http://www.zohowebstatic.com/sites/zweb/images/survey/features/multiple-response.png)
CAPTCHA
Enabling CAPTCHA protects your survey against automated responses from internet bots. CAPTCHAs use images that bots can't scan to verify that only real people are responding to your survey.
![secure-survey-captcha](http://www.zohowebstatic.com/sites/zweb/images/survey/features/secure-survey-captcha.png)
SSL Certification
SSL (Secure Sockets Layer) establishes a secure connection to the server for your respondents. Zoho Survey comes packaged with SSL protection.
![ssl-certification](http://www.zohowebstatic.com/sites/zweb/images/survey/features/ssl-certification.png)