Too Long; Didn't Read
Security For PMs: How-To [Part II] explains how to ensure that your security practices are working. Don't neglect taking the time on the very first stages of the project to write the security requirements. Creating a one-pager with basic rules is much cheaper than re-doing the whole product. The earlier you start implementing security practices, the cheaper they will be. Don't be afraid to bring up this topic, be honest and don't be shy to invite the security experts from your client.