Re: Data encryption
Re: Data encryption
- Subject: Re: Data encryption
- From: Jens Alfke <email@hidden>
- Date: Wed, 06 Jun 2012 10:50:02 -0700
On Jun 6, 2012, at 10:24 AM, Charlie Dickman wrote:
> I have an application on OS X, not IOS, that contains some sensitive data that I want to withhold from those not licensed to use it. I wish to use RSA encryption/decryption in block mode (I think).
It sounds like the data is hardcoded into, and distributed with, your app, but encrypted, and when the user gets a license they'll be provided with a key to decrypt it?
That sounds more like a case for a symmetric cipher, not RSA. You make up a key, then encrypt the data with it when you build the app. When a user registers, you send them the key, and the app can then use it to decrypt the data.
> I want to encrypt both the public and the private key and I think I want to use (at least) 128 bit techniques although 64 bit would probably do.
128-bit would be better. Although in this use case no one's going to try to brute-force decrypt the data; they'll just look around on a warez site for the key that some earlier unscrupulous user has uploaded.
> I plan to re-encrypt the keys after each use.
I'm not sure what that means. I *think* you're referring to keeping the decryption key secure on the user's machine? To do this you'd add it to the keychain.
The API you want is probably the one in <CommonCrypto/CommonCryptor.h>. AES128 is good default algorithm to use. To access the keychain use <Security/SecKeychainItem.h>.
—Jens
_______________________________________________
Cocoa-dev mailing list (email@hidden)
Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden