All traffic on Trello runs over SSL/TLS/HTTPS, the most common and trusted communications protocol on the internet. Data is backed up hourly and copies are stored at an off-site location for disaster recovery. More detailed security information is available upon request.
Your data is yours. If you ever want to stop using Trello, you should be able to download your data. Trello features data portability where applicable. We strongly believe in it.
To export your data, simply open a card or open the sidebar Menu, then click the 'Share, Print, and Export' button, and you'll find export options. Currently, we allow export to JSON, which is a format that lends itself well to Trello's specific data storage model. For options to export to Excel, see Exporting data from Trello.
Please submit your report on HackerOne and our security team will respond as soon as possible.
Thanks to the following individuals, as well as the individuals listed on our HackerOne page, for responsibly disclosing a security vulnerability in Trello: