I have been searching for a diary/journal application for the iPad that will encrypt the contents of the journal. Though there is no shortage of journal and note taking apps I have yet to find one that specifically mentions that the user content is encrypted while on the device. Does iOS provide APIs to allow for AES or similar encryption (Blowfish etc ...)? Is it difficult to encrypt user data within an iOS application?
Just to clarify ... I am not talking about simple password protection but rather encryption of the user data such that if the iOS device were compromised the user data would be unreadable.