How secure is the data your iPhone(s aapl) or iPad? A little less than perhaps you thought, according to Jonathan Zdziarski, who has a slideshow of findings that may surprise you. A security researcher with several books to his credit, Zdziarski suggests that 600 million iOS devices have built-in backdoors and undocumented services put in place by Apple.

Zdziarski’s slides came to light on Monday through ZDNet and were used in a recent conference talk he gave called “Identifying Backdoors, Attack Points, and Surveillance Mechanisms in iOS Devices.”

The full set of slides are available in a PDF download here, but some of the highlights include:

• Library and cache files are not encrypted although since iOS 7, third-party documents are.
• Some of the undocumented services in iOS — “lockdownd,” “pcapd” and “mobile.file_relay” — can get at encrypted data for access over USB and perhaps thorough a cellular connection.
• Third-party forensic software…