Is there a log or similar I can import to assure people that form is secure?

We are asking people for personal details to book them on a flight

Please check this guide: http://www.jotform.com/help/344-What-are-Encrypted-Forms-and-how-to-use-them-as-expert.

The feature allows you to collect the data and store it in encrypted form and allows to to view the data only if you have decryption key.