Apple announced that it would implement Advanced Data Protection

Apple announced that it would implement Advanced Data Protection (ADP) for iCloud, which uses end-to-end encryption. That means that only the user with an authorized device can access data in the associated iCloud. 

Effectively, that is an exact technology used for private key storing in the blockchain. For example, in Trust Wallet, the private keys are stored on the device that downloaded the app, which will be the only device that can access these keys. Even the developers of Trust Wallet will not be able to access the generated private keys.

The technology is scheduled to be implemented at the beginning of 2023. With ADP, even police or intelligence agencies cannot force Apple to share users' private data. This might have a positive impact on data privacy and a negative impact, too, as data of suspected criminals and terrorists will become inaccessible to law enforcement agencies because the company will not have the ability to do so anymore.