asked on

Need encryption for my app's generated files

I am writing an iPhone app using Xcode/Objective-C and need to encrypt the files my app generates and then subsequently accesses. What prebuilt library can I use to do this?

I would like it to be secure and "virtually impossible" to defeat without the key (and password?) that I intend to embed in the source code of my program. The files will be text, image and audio. Also, I plan to make an Android version of my app and want it to be able to access files created with my iPhone version.

So really, I need my choice of encryption software library to fit my cross platform strategy for my app.

What can you suggest?

I would prefer free, but would consider a paid version that had a "per developer" license, if that enabled me greater flexibility.

Hope to hear some great alternatives.

Thanks.

darbid73

Hi newbieweb,

Are you still working on the same app or is this a new one. I find encryption very difficult to understand. You talk about inbuilt and free. Thus I would think about encryption with NSData.

First there is some very simple encryption things on iOS Protecting Data Using On-Disk Encryption. But I am not sure you are looking for this.

I assume you have a developer account so Here is what the apple developers said last year about this.

Look at the answer to this question and to the linked files.

I Googled this link but have not tried it.

curiouswebster

ASKER

I think encryption with NSData is the right choice.

Does it work reliably?

I read this:
DISCLAIMER: There no guarantee my NSData+AES is bug-free :) It's fairly new. I welcome code reviews.

in the third link you posted "Look at the answer...".

But here's another question...

Can this technology work cross-platform? What tools could I use to open these files from Android using Java or some other language?

Thanks.

ASKER CERTIFIED SOLUTION

darbid73

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

curiouswebster

ASKER

Does this mean the App Store will require special time to review it? Any idea how much longer that takes?

darbid73

Instead of me simply typing it again have a look at the first answer here to s imilar question. Generally he has a good point and has some links you can look at.

curiouswebster

ASKER

Thanks! You saved me a lot of work and some serious frustration, getting the bad bad news from the App Store. I decided I can generate an authentication token instead, and insert that into the XML file. On opening the file, I will reject the file if it has been edited by hand.

darbid73

Thank you . I am interested too in your line of questioning so I am watching your other question.

curiouswebster

ASKER

https://www.experts-exchange.com/questions/27932657/Need-an-alternative-to-encryption-for-my-iPhone-app.html?anchorAnswerId=38593532#a38593532