The security issue is still a big challenge for data systems in the era of big data, which the data science is playing a more and more critical and central role in the development of cyberspace and various applications. Researchers and developers pay much attention to propose novel theories and technologies to countermeasure the security issue. The 2017 International Workshop on Data Systems Security (WDSS 2017) hopes to play an important platform to help that these researchers and developers exchange their ideas, designs and system implementations.