iCloud deletion

Question

If I delete photos which are stored in iCloud from my phone. (Which is also linked to my iPad)

I know the data is then made ‘free space’ but is still on the phone In some format.

If I delete it from my phone, it’ll also delete from my iPad, but will it stay in my iPad as ‘free space’ even though it was originally deleted from my iPhone?

Also, if I did a backup on my iphone after deleting files, would the backup recognise those deleted files as free space and include them in a restore on a new phone? (Hopefully that makes sense)

Answer 1

Any device that has ever stored your photos will persist them on the disk until they are overwritten. Devices include your iPhone, iPad and iCloud's servers. Deleted images that have not been overwritten yet may be recoverable using software tools. Malware can do this without your knowledge.

It is not advisable to sell your iPhone or iPad, since having access to the device makes it much easier to recover deleted data. Drill several holes in the device before disposing of it, but take out the battery first to reduce fire hazard.

Deleted photos will not be present in any way in a backup you have made on a separate device, if you've deleted the data from your deleted/recycling folder before starting the backup.

Answer 2

WRT 'I know the data is then made ‘free space’ but is still on the phone In some format.':

Since iOS 10.3, the file system uses file-level encryption, where each file is encrypted using a unique key. When a file is deleted, the key is purged. So, even if you could read the blocks previously used to store the file, you would have no way of decrypting these blocks without the key. See https://blog.elcomsoft.com/2021/11/the-five-ways-to-recover-iphone-deleted-data/ for a good write-up about this.