Fast Chargers May Require USB-C Authentication to Work at Full Speed With 2018 iPhones - MacRumors
Skip to Content

Fast Chargers May Require USB-C Authentication to Work at Full Speed With 2018 iPhones

by

Rumors suggest Apple will bundle a faster 18W power adapter with its next-generation iPhones, expected to be unveiled this September, but third-party fast charger compatibility may be limited.

2018 iphones fast charger c auth
Japanese blog Mac Otakara, citing information from suppliers, claims that third-party fast chargers may require USB-C Authentication [PDF] certification, or C-AUTH, to charge the 2018 lineup of iPhones at full speeds. Otherwise, the iPhones may display a warning, and limit charging speeds to a max of 2.5W.

USB-C Authentication is intended to protect against non-compliant USB chargers and to mitigate risks from maliciously embedded hardware or software in USB devices, so core to Apple, this seems to be all about extra security.

Apple is one of over 1,000 member companies of the USB Implementers Forum, so USB-compliant fast chargers are available from a wide variety of brands. Before purchasing a random fast charger from the likes of Amazon, though, it may be a good idea to check the list to see if the company is in fact a member.

Tags: Fast Charging, USB-C
Related Forum: iPhone

Popular Stories

Dynamic Island iPhone 18 Pro Feature

11 Reasons to Wait for the iPhone 18 Pro

Monday May 11, 2026 9:01 am PDT by
We're only four months out from the launch of Apple's premium next-generation smartphone lineup, and while we're not expecting a sea change in terms of functionality, there are still several enhancements rumored to be coming to the iPhone 18 Pro and iPhone 18 Pro Max. One thing worth noting is that Apple is reportedly planning a major change to its iPhone release cycle this year, adopting a...
Read Full Article • 35 comments
iOS 26

iOS 26.5 Features: Everything New in iOS 26.5

Monday May 11, 2026 5:09 pm PDT by
Apple released iOS 26.5 after a few months of beta testing, and while it doesn't have the Siri features we were hoping for since those are being held until iOS 27, there are a handful of useful changes worth knowing about. Subscribe to the MacRumors YouTube channel for more videos. End-to-End Encryption for RCS Support for end-to-end encryption (E2EE) for RCS messages between iPhone and...
Read Full Article • 65 comments
General Apps Reddit Feature

Reddit Starts Blocking Mobile Website, Pushing Users to App Instead

Monday May 11, 2026 6:10 am PDT by
Social network Reddit recently began blocking mobile visitors to its website while pushing them to download the official Reddit app, and it's fair to say that the move is not going down well with users. If you visit reddit.com on your iPhone today, you may see a new popup that can't be dismissed, asking you to "get the app to keep using Reddit." A Reddit spokesperson told Ars Technica...
Read Full Article • 125 comments

Top Rated Comments

Andres Cantu Avatar
Andres Cantu
102 months ago
Apple loses either way: if they do this, people will complain that Apple is being closed as usual.

If they don’t and iPhones start exploading because of possible uncertified shady chargers, then Apple gets the heat as well.
Score: 30 Votes (Like | Disagree)
L
logain
102 months ago
Ah, yes, security reasons. Specifically, the security of being able to charge $10 / piece for an encryption key.
Score: 18 Votes (Like | Disagree)
zorinlynx Avatar
zorinlynx
102 months ago
Why is the fallback speed 2.5W? Shouldn't it be at least 5W, which is the power that 99% of chargers support?
Score: 16 Votes (Like | Disagree)
69Mustang Avatar
69Mustang
102 months ago
Apple locking users into expensive cables and chargers again!

Although from a safety perspective I can understand why they are following this route too!
Are you confusing C-AUTH with MFi? One has nothing to do with the other.

Apple loses either way: if they do this, people will complain that Apple is being closed as usual.

If they don’t and iPhones start exploading because of possible uncertified shady chargers, then Apple gets the heat as well.
Closed how? Plenty of companies offer accessories that meet C-AUTH specifications. That has nothing to do with Apple.
[doublepost=1532354111][/doublepost]
Yeah... but there is an easy way to fix that WITHOUT locking out 3rd party chargers: require specific user authentication to enable DATA in addition to CHARGE.

Thus:

(1) Plug into any charger and get power
(2) IF you also want to transfer data, unlock the phone and choose "OK" to enable data transfer
(3) Optionally enable THIS DEVICE to always permit data

Problem solved... without vendor lock.
This doesn't lock out 3rd party chargers. This isn't MFi. It's C-AUTH.
Score: 14 Votes (Like | Disagree)
Pupi Avatar
Pupi
102 months ago
Ah, yes, security reasons. Specifically, the security of being able to charge $10 / piece for an encryption key.
Apple MFI certification is already done on the charging cable. This is about limiting fast charging on the powerbrick side of things to authorized and safe chargers. C-AUTH isn’t an Apple standard nor uses an Apple chip or results in a royalty paid to Apple.

-Pupi
Score: 12 Votes (Like | Disagree)
jclardy Avatar
jclardy
102 months ago
This is fine with me...as long as Apple's existing USB-C chargers are already compliant. This will be extremely stupid if the 29w charger I have for fast charging my iPad won't work for fast charging on a new iPhone. It is already incredibly stupid how much I have to swap around cables between lighting/USB-C for my latest Apple hardware.
Score: 12 Votes (Like | Disagree)
Read All Comments