iCloud Private Relay

iCloud Private Relay traffic and IVT

What is iCloud Private Relay?

iCloud Private Relay (iCPR) is a privacy offering from Apple that is intended to protect users' privacy by hiding their IP addresses. This is only available to paid subscribers of iCloud+,

Note - HideMyIP is a different (free) feature from Apple which uses the iCloud Private Relay infrastructure and IP ranges, but only obfuscates the client IP address from "known trackers".0

Why is it important?

When Pixalate conducted a study of iCloud Private Relay traffic, we described the general findings related to iCPR traffic, and the potential exploit. A second report in November 2022 dove deeper into the suspicious behavior we saw in the traffic, which we dubbed iP64.

How does Pixalate's Analytics Dashboard help with iCPR?

Pixalate has introduced two features to help analyze your ad traffic.

  1. New iCPR IVT Type
    A new iCPR-specific IVT type called “maskediCloudRelayIP” to cover this form of IVT where the declared IP lies in the iCloud Private Relay range, and demonstrates suspicious behavior, including
    • Traffic originating from an invalid data center IP range;
    • Traffic that has inappropriate device types associated with it, and;
    • Traffic featuring suspicious patterns and associations.

  2. New iCPR Report
    A new iCPR pre-set report in the Analytics dashboard that distinguishes your valid and invalid iCloud Private Relay traffic in one place.

Impact of maskediCloudRelayIP IVT on total IVT
The new “maskediCloudRelayIP” IVT subtype, is a carve out of the "maskedIP" IVT type, and so will not increase the total IVT rate.The overall rate might decrease because we are only marking a subset of the iCPR mismatch traffic as maskediCloudRelayIP IVT, based on demonstrated suspicious behavior.

Note - Even though the total IVT will not significatnly change, the amount of “maskedIP” IVT will decrease proportionally.


New pre-set report - "iCPR Traffic Report"

This new report will take all your iOS and MacOS Safari traffic and give you the ability to break it down by domain, seller, iCPR type, and more.


Sample Screenshot

The dimension “iCPR type” lists all the forms in which iCloud Private Relay IPs have been seen in your traffic with the following possible values:

Declared only Declared in the bid request to be iCPR, but when checked by Pixalate, found to not be an iCPR IP address
Detected only Not declared in the bid request to be iCPR, but when checked by Pixalate, found to be an iCPR IP address 
True iCPR Both declared and detected to be iCPR (Note - this does not automatically mean "free from IVT")
Non iCloud Relay Neither declared not detected to be an iCPR IP Address