Hugh Pickens DOT Com writes: Bruce Schneier writes that the three characteristics of a good backdoor are a low chance of discovery, high deniability if discovered, and minimal conspiracy to implement and says that the critical iOS vulnerability that Apple patched last week meets these criteria and could be an example of a deliberate change by a bad actor. "Look at the code. What caused the vulnerability is a single line of code," writes Schneier. "Since that statement isn't a conditional, it causes the whole procedure to terminate." If the Apple auditing system is any good, they will be able to trace this errant goto line to the specific login that made the change. "Was this done on purpose? I have no idea. But if I wanted to do something like this on purpose, this is exactly how I would do it."