Keyboard Cache Storage Questions

Morrisseyfan84 wrote:

Hey guys; so, from my understanding iOS devices have a cache where literally everything typed in to the device is stored. I'm curious about how this works and I can't really find any information on it. How does it store this information? Does it store words by themselves in alphabetical order or does it store whole sentences and phrases together? Also, I'm curious if this records while Private Browsing is on as well?

Literally not true. The keyboard cache does not, and never has, captured anything typed in an iOS or 3rd party app text field designated as a secure field. So no passwords or personal ID information used with autofill or typed by you are saved to the keyboard cache.

And my understanding is it is not related to the keyboard itself, but to autocorrect, so it is selective things not in the iOS dictionary. Also, 3rd party keyboards may have their own separate cache, and some even send data to the developer so users need to pay attention to what keyboards they use and what settings they enable with them. Android and windows mobile OS, btw, do the exact same thing. Autocorrect has to retain a history of non-standard or pre-programmed words somewhere.

Developers on various discussion forums confirm that disabling autocorrect disables the primary iOS cache ( but note may not disable a 3rd party keyboard cache).

By and large, yes. Autocorrect uses the built in dictionary, but it has to have a lookup cache or database of the things that you've actively corrected it for when typing. As I mentioned, any text field in any app flagged as secure is dis-allowed from any such caching (secure autofill fields can be populated from other cached data though, such as iCloud keychain fields in Safari).

Also note that even the autocorrect cached data, on devices with a fingerprint sensor and running iOS 9 or higher (maybe even 8, but my memory of some of these changes gets hazy as time passes) is encrypted, as is all user data on new(er) devices.

To be honest, if you are worried about caches of things you type, it is 3rd party keyboards to be wary of. And it's not local caching to be worried of there, but those that send data to developers. While there are legitimate uses of such data by developers, and they will collect it anonymously, it is something to check out before you install or use any 3rd party keyboard if you feel uncomfortable about anyone else knowing what you type (some also, if you enable full access data collection, send location data, and other data as you type and use them). Although, to be accepted into the App store, any 3rd party keyboard/KB-extension must have a displayed privacy policy popup, so you know what it is doing when you install it. They do not, however, have to have the ability to disable data collection - they just have to tell you what they are doing if you use them.

Hi. Where did you obtain this understanding? I know that iOS maintains a user dictionary of misspelled words that were accepted by the user, but that's not a cache of all input.

the char of the pressed key are cached separate, all keyboards does it if you hold down a key on some computers and it begin to beep it's because the buffer is full

Interesting. However, that doc is at least 4 years old, and countless full releases of iOS out of date. So there's no way of knowing if it continues to apply. Maybe ask the FBI .

Note that article is 4 years, 5 iOS releases and 6 iPhone models out of date (article is from 2012, so iOS 5 and iPhone 5 era - ancient and out of date by tech-time).