You have two mistakes in this sentence.
1. None of the iCloud data (mail, docs, drive, etc.) is E2E encrypted. Some of the data stored in iCloud (like keychain backups) is encrypted prior to being sent to iCloud (using symmetric encryption, not with asymmetric key pairs). China has access to the data that was ultimately sent to iCloud.
2. The way Apple implements E2E encryption for services like iMessage that are E2E encrypted allows China access to that data.
> If the private key is generated by the same entity or “key server” that generates the public key, and then transmitted to the client.
That's the point. Since Apple's implementation relies on a key server to distribute public keys, it is straightforward for the key server to generate its own key pair and serve a fraudulent public key to the recipient, decrypting and re-encrypting messages that the iMessage servers relay. Apple relies on the technical illiteracy of its users to get away with its deceptive and often plain false marketing claims. Now you know better.
But after reading research from security experts you have found a citation where Apple is generating a key pair from its servers and sending the private key to the client?
That's the point. It should not, but the security model of iMessage allows the key server to get away with it, which is almost certainly happening in China right now. Try reading the article and following the example.
> But after reading research from security experts you have found a citation where Apple is generating a key pair from its servers and sending the private key to the client?
No, it sends the public key. Encrypting messages is done with the recipient's public key. Go read the Wikipedia article on asymmetric encryption. Because the owner of the keyserver can send its own public key, it can decrypt messages with its own private key before re-encrypting with the intended recipient's public key.
But since it’s in a Wikipedia article, I guess that kind of closes the case.
You once again misunderstand the vulnerability. The vulnerability is that China does this because China controls the keyservers in China.
As far as anybody discovering this, that would be very difficult because Apple does not let you install your own apps on the device and would not approve an app designed to detect this.
But even more, why would they bother? People who care about their privacy will simply avoid closed source software and especially closed systems like Apple's instead of trying to use a known compromisable system safely.
>But since it’s in a Wikipedia article, I guess that kind of closes the case.
I was pointing you to a place where you could learn about cryptography because you seem not to understand the basic concepts. The Wikipedia article does not describe this particular vulnerability.
If some of the data is e2e encrypted using private keys,China doesn’t have access to “all data”
Those same standards don't actually protect your data from whoever controls the iCloud server or whoever controls the iMessage key server.
If the private key is generated by the same entity or “key server” that generates the public key, and then transmitted to the client. That kind of defeats the entire purpose of public/private key encryption.
I’ve never seen an implementation of public/private key encryption where the client device doesn’t create the key pair and send only the public key to encrypt data.