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

Apple Event Logo

Apple's Next Era Begins September 1

Thursday May 7, 2026 10:36 am PDT by
Apple recently announced that Tim Cook will be stepping down as CEO later this year, after 15 years of leading the company. Effective September 1, Apple's hardware engineering chief John Ternus will become the company's next CEO, while Cook will become executive chairman of Apple's board of directors. In his new role, Apple said Cook will assist with "certain aspects" of the company,...
Read Full Article
Four iPhone 18 Pro Colors Mock Feature

iPhone 18 Pro Launching in September With These 10 New Features

Saturday May 9, 2026 6:03 am PDT by
While the iPhone 18 Pro and iPhone 18 Pro Max are not launching until September, there are already plenty of rumors about the devices. It was initially reported that the iPhone 18 Pro models would have fully under-screen Face ID, with only a front camera visible in the top-left corner of the screen. However, the latest rumors indicate that only one Face ID component will be moved under the...
Read Full Article
Apple Watch Series 10 Jet Black Touch ID

Apple Watch Series 12 and watchOS 27: What to Expect Later This Year

Friday May 8, 2026 2:07 pm PDT by
While not too much has been reported about the next Apple Watch models, there are a few rumors about potential design changes and watchOS 27 features. Apple Watch Series 12 and Apple Watch Ultra 4 models are expected to be released in September, and we have outlined some of the key rumored hardware and software changes below. A new Apple Watch SE is not expected this year, as that model was...
Read Full Article • 59 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