In a report from a researcher at Azimuth Security this week, it was revealed that the upgrades the random number generator on iOS went through between version 6 and 7 may have actually done more harm than good, and that the mobile OS could be vulnerable to attacks designed to take advantage of this newly minted weakness.
According to a blog written by Tarjel Mandst,
“An LCG is an algorithm that yields a sequence of random numbers calculated with a linear equation. LCGs are one of the oldest and best-known pseudo-random number generator algorithms, and are commonly leveraged in standard libraries and applications for being fast and easy to implement. Although these algorithms perform well in resource-constrained environments and have appealing statistical properties, they exhibit some severe defects and are easily broken when confronted by an adversary who can monitor outputs”
In plain English, essentially this means that the PRNG system used to lock the phone’s local encryption at the beginning of each boot has the potential to be corrupted, that is if someone is monitoring its external outputs at the same time.
Although the vectors for infection come with some very specific guidelines, this shouldn’t deter anyone from taking the threat as seriously as they would any other daily security update.
The company has yet to respond to Mandt or his allegations regarding their random number generators, but we’ll keep you current on any developments as soon as they hit the wire.