Fast Chargers May Require USB-C Authentication to Work at Full Speed With 2018 iPhones - MacRumorsOpen MenuShow RoundupsShow Forums menuVisit ForumsOpen Sidebar
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

iOS 27 Next to iPhone

Here's When iOS 27 Rolls Out Today in Every Time Zone [Update: It's Out]

Sunday September 13, 2026 3:00 am PDT by
Update 10:04 a.m.: iOS 27 is rolling out now, though it may take a bit for all users to see it, so keep checking! Apple is about to release iOS 27, which will finally deliver more advanced Siri AI capabilities as well as a variety of other refinements, improvements, and new features to iPhones. It's Apple's biggest software update of the year, and Apple announced at Wednesday's iPhone event...
Read Full Article • 151 comments
iOS 27 Icon iPhone

iOS 27 Available Today With These 8 New Features

Monday September 14, 2026 9:00 am PDT by
Update: Apple has released iOS 27. During its iPhone 18 Pro and iPhone Duo event last week, Apple announced that iOS 27 will be released widely on Monday, September 14. iOS 27 should be available around 10 a.m. Pacific Time / 1 p.m. Eastern Time today via the Settings app, under General → Software Update. Below, we have highlighted eight new features and changes coming with iOS...
Read Full Article • 110 comments
deep black iphone 18 pro

Apple Says iPhone 18 Pro Max Sold in U.S. Differs in One Way

Saturday September 12, 2026 3:27 pm PDT by
As noted by Nicolas Lellouche, who writes for the French tech website Numerama, Apple has updated its tech specs pages for the iPhone 18 Pro and iPhone 18 Pro Max to clarify which models are equipped with its new C2 cellular modem and where. Apple now says the iPhone 18 Pro has a C2 modem worldwide, while the iPhone 18 Pro Max uses the chip in every country except for the U.S. According...
Read Full Article • 136 comments

Top Rated Comments

Andres Cantu Avatar
Andres Cantu
106 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
106 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
106 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
106 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
106 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
106 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

🔗 Related Apple News & Rumors

Stay updated with the latest Apple ecosystem news and verified rumors