Security Services data usage

Got the exact same issue. Seems that Security services is gobbling insane about of data. I've captured the data being sent over the cell network (everything is secured using TLS 1.2 or 1.3) but end up on the 17.0.0.0/8 subnet. So it's data sent back and forth with Apple owned Services, and cannot be controlled by the user (or it's background tasks that is doing this).

Because of the secure nature of the network traffic, it's hard to guesswork what it being used and the logs don't seem to give any insights. However, one thing is for sure, it's something tied to the AppleID. One thing worth mentioning, this network traffic is also happening on Wi-Fi but since most Wi-Fi access are unlimited or with high caps, it's not noticeable. But turning off data and only using Wi-Fi showed the same odd traffic pattern. The fact it's happening on cell network is just more observable.

I've logged out of my AppleID on my device, restarted it (shutdown and cold boot) and there is no further traffic (or very little)

Opened up a case and entered a bug report on the dev website, but so far, very little seems to be known about this right now. I'm somehow happy to see I'm not insane and not the only one having issues like this, and moreover happening on various carriers (even more intriguing)

Would be nice to see if those affected are using family sharing feature or not.

The problem seems to affect all devices logged in iCloud (Mac and iOS), so it helped me track down the problem. Did some further digging, logs analysis and lots of packet capture and finally found a tidbit in a log file. It seems that my problem was tied to some issue syncing the Keychain information. There was an entry in the logs stating the "item was too big" and it was probably looping. I deactivated all keychain on all logged in devices, removed the cloud keychains from the Mac (the folder in ~/Library/Keychains with a UUID string) and restarted. Turned off Keychain sync on iPhone. And BAM! went from over 5 GB/h in network usage (on Wi-Fi) that ended up being tied to this "security service" (Determined by packet capture) to about 133Kb in the last 24h for the same traffic (left the device for 2h on cell data, no Wi-Fi and it barely used any data) Turning back on the keychain spins up the data again to an alarming rate. Turning it off (Keychain) solves the issue. Somehow, it will probably need an erase and restore of the iPhone to get rid of the "corrupted" local keychain data but the Mac are no longer sending massive amounts of useless data.

So check your keychains on all devices, this would be a first step to see if anyone can fix their issues.

That being said, hope for a more permanent fix soon.

Hello. Here is something that worked for me but it is quite painful and requires work and time (did it over the weeked). My phone is an iPhone 11 Pro Max with iOS 14.4.2. In addition to having tried network reset, full erase, reintasll of iOS 14.4.2 from the phone and from my Mac as suggested by the Apple call center. Finally and wath solved the problem, I completely erased it again (the erase All Content and Settings option) and I set it up as a new phone. Before doing that, I backed up everything that can be backed up on iCloud and then restored it from there. I installed the apps one by one manually. It took me a few days to get the phone back to the way it was before (I say similar because now it is optimized) but the important thing is that the problem of disproportionate data ussage from security services has been solved. It's been a week since I did all this and security services has not used a single Kb of my cellular plan. I repeat, this solution is painful and requires effort but it worked for me. I hope it helps too.

Full reset and install apps one-by-one did not resolve the issue for me.

But, sign-out of Apple ID did stop the traffic. And it's also possible to sign into Apple ID for music and Apps without starting the traffic.

As soon as I enabled iCloud the traffic was back. So, it's an iCloud sync issue I'm guessing.

@Spiderdaimi, @J_Tsags007, and others,

I think I have addressed the issue. Here is my current working theory and where my devices stand now.

I'm still pretty confident that it was a corrupt keychain issue. One keychain item or the whole keychain, it doesn't really matter. What mattered was that every device I was syncing this keychain to was showing some form of the same clobber-all-upload-bandwidth issue, AND I could not turn it off. I'm in a pretty good place now, and here is what I did to get there:

• Sign out of my iCloud account on all devices.
• Log into iCloud.com and change the password. Select the option to force a logout to get any devices I may have missed (looking at you, TV). I hadn't changed this password in far too long.
• Log back into iCloud on my MBP and quickly disable keychain sync. I selected the option to keep a local copy of my passwords.
• It stuck this time. I waited for about 20 minutes, opened/closed System Preferences more than once to keep verifying, and even rebooted the laptop twice. It stuck (Huzzah!).
• There was a flurry of upload and download activity to and from the cloudd process for these 20 minutes, which was expected, then sweet, sweet quiet (on the network).
• I gave it a bit more time, then logged into iCloud on my iPhone, and... Success! The Keychain sync switch was still in the off position. Once again, saw significant up/down network traffic for about 20 minutes, then sweet, sweet quiet.

I still haven't re-enabled keychain sync yet. Will probably try that tomorrow some time after confirming my iPhone's battery life has been restored. My phone has been remarkably cool to the touch all morning too. I believe that the local device password is used in combination with your iCloud to encrypt the keychain data. I think somehow that process got corrupt on all of my devices, and changing the iCloud password forced a re-encryption process that fixed the issue. At least that's what I'm hoping happened and this frustrating chapter of my iCloud life is now behind me. I'll post again if the problem returns, but consider my radio silence from here on out to be a Good Thing®.

Hope this helps!

Tap Settings. Tap your name at the top. Tap iCloud. Turn off the switch for Keychain. What happens next?

If it doesn’t turn off, can you sign out of iCloud?

Do you have a company/school email account on your phone, or is it controlled in an MDM (Mobile Device Management) environment?

Go to Settings/Screen Time. Is it on? If it is go to Content & Privacy Restrictions. Are all of the Allow Changes switches on?

After getting iCloud to sign out on all my devices by changing the password elsewhere, and then enjoying the battery life, phone that was cool to the touch, and available upload bandwidth, I turned iCloud keychain syncing back on.

Boom. Instantly miserable. Poor battery life, warm phone, and clobbered upload bandwidth. Turned it back off within an hour.

Since this isn't affecting everyone, I suspect it's a corrupt Keychain item that iCloud doesn't know how to handle. Before resigning myself to patiently waiting for the next iOS update and trying again, I may try one final troubleshooting step. I have a few old Macs in the basement and may load up an older version of MacOS that still had the "Repair keychain" option in Keychain Access.app. A cursory Google search shows it was removed in OS X 10.11.2.

I apologize if this post is a duplicate of others, but I had an agonizing time with this data issue. Up to 10 calls into Apple support, resulting in hours on the phone and Apple actually issuing a replacement unit. The problem still persisted at the 900.00MB transfers every 20 minutes or so. The only thing that has solved this is turning off keychain. This has eliminated the issue entirely. I saw that some people cant shut it off, which I have zero insight on. I am not a technologically advanced user at all, so I apologize for that. I don't even know what Keychain does but its not draining my data anymore.

I tested the issue as Hoodlehead suggested, but without changing the password. I logged out from the iCloud services on all devices, and logged in back. The process was easy, just need to add the cards again to your wallet, the traffic cards were to be added back without iCloud (it was my only worry, I thought they could disappear). After that the functionality to turn off Keychain and turn back at will was restored (with occasional multiple tries). The security traffic problem was solved when the keychain was off. After turning back the keychain the issue is coming back. It is invisible on iPad, but it is there, the iPad becomes much slower with time, I strongly believe it is affecting iPad too. I could try to change the password as Hoodlehead suggested, but I don’t believe it will contribute to anything, however if he has tried that and turned back his keychain, and that solved for him, I could try that too. So, we can look forward to his report. Apple should solve this problem, please.

[Edited by Moderator]

Same problem here.

Switching off the icloud keychain option will stop the irregular massive data traffic of system/security.

Checked the keychain sizes on the mac, just a few MB, but lots of secure notes with some PDF files in.

Also wasted a lot of time with Apple Support, spent some money on additional mobile data volume and even changed the battery.

:(

@hoodlehead

I'm making a useless phone less useless by sign-out of Apple ID. That stops the traffic. And it's also possible to sign into Apple ID for music and Apps without starting the traffic. As soon as I enabled iCloud the traffic was back, so I don't do that before there is some sort of fix out.

I did exactly the same steps and without Keychain sync on, my battery life and bandwidth are awesome.

As soon as I turn it on, the nightmare starts again.

I have tried to delete, reset my iCloud keychain, cause I'm sure like hoodlehead that my keychain is corrupted.

But until now all what I tried did not succeed, and Apple Support is not calling me back anymore.

I had the same issue, my iPhone was eating 2.5gb of data every day. I spoke with Apple Support and they suggested that I turn off WiFI Assist and iCloud Drive in Settings/Mobile Data, which seems to have resolved the issue. As I work from home this works for me.

Have you tried disabling iCloud Keychain on the affected device? This solved the problem for a few of us.

Apple Support was a waste of time.

Switching off iCloud Keychain helped ...