Encrypted Diary

Hi Amit,
In this era of NSA Prism, the concept of a personal diary where you can write your thoughts and experience is threatened. So, I am looking for an Encrypted Diary. Or just an encrypted notepad where we can sort by date and search for keywords like Evernote. But the main point is some standard trusted encryption. It would be great if it could be a great article in labnol. I personally have a MacBook Pro. But a cross-platform app that can run portable might be the most secure solution. But I lack technical skills and I hope with your skill and popularity, you can find the right app or atleast get a opensource project started for it.

Thank you.
ak