While there were early reports that this might be the case, 9to5Mac has confirmed the news.
We first spotted this in a Reddit post, and have since confirmed. The warning message itself is unchanged, but it’s no longer an empty threat – though as seen in comments, some non-certified cables are still working. Possibly ones that use cracked chips. The good news is that there is a workaround for others, but it’s not pretty …
Reddit user 3quanimity suggests trying:
1. Turn on USB power
2. Plug in lightning cable to iPhone
3. Dismiss any warnings
4. Unlock your iPhone.
5. Dismiss any remaining warnings.
6. Now with the screen turned on.
7. Unplug the knock off lightning cable.
8. Plug it back in.
9. Dismiss warning again
10. It should now charge.
Apple's authentication for the Lightning connector was cracked in October 2012 allowing third party companies to manufacturer accessories without approval. Presumably, Apple has found a way to detect whether its authentication was bypassed and has included this check in iOS 7.