The CBC-MAC mode is not a parallel one. A parallel authentication mode (PKCB) based on double blocks was put forward in this paper.

由于CBC - MAC模式不可并行处理，提出了一种基于双重分组的并行认证模式(PKCB)。

youdao

We weren't able to get it working in USB debugging mode on our Mac, either, though we were able to download media to Image Capture without a problem -- it seems as though the computer is treating the phone as a camera, not a drive.

ENGADGET: Epic 4G review

Did we mention how much the un-Sony-like mass-storage mode warmed our jaded (and occasionally Mac-using) hearts?

ENGADGET: Sony Reader PRS-505 (second gen) hands-on: we're in love