Bitbucket: Bitbucket Cloud Security Statement
The security of your data is very important to us. While data storage is not encrypted, access to your code is limited to a very small number of engineers on our team. This access is logged. Access by anyone else is controlled by Bitbucket permissions, so if your code is private, only you and the above engineers will be able to access it.
The following links contain our security policies and procedures:
Also, Bitbucket now offers IP whitelisting & required 2-Step Verification.
When complementary security dispositions become the main requirement, we advise to host the Server version of Bitbucket on your own infrastructure, or on a 3d party Cloud hosting provider (Amazon, Azure,…), or work together with one of our certified Atlassian Solution Partners who can offer localized or custom managed hosting services with additional flexibility.
For more information see our document How secure is my code on Bitbucket? Is the service reliable?.