What is my boyfriend changed his phone password?

As an AI language model, I do not have access to personal information about specific individuals. However, changing a phone password is a common practice for many individuals who want to secure their personal information and protect their privacy. It could be a sign that your boyfriend values his privacy and wants to keep his personal information safe. However, if this change in behavior seems out of character and causes concern, it may be worth having an open and honest conversation with your boyfriend to discuss any potential issues.