A few questions about encryption and decryption
I'm working on an app that I might potentially want to market. I want to encrypt some of the information, and then have the user be able to "recall" that information, which then decrypts the string.
I want this to have a good amount of security, so it brings to mind a couple of questions:
1. What is a good encryption algorithm to use that I can also decrypt with? So, if I store, let's say, a piece of information that a user might need to retrieve, they can recall it unencrypted to use.
2. If I were to go about writing my own encryption/enciphering algorithm (with a private key), where would be a good place to store the key where it is not easily discovered? Additionally, here, I would want multiple keys, so that basically each item to be encrypted would have it's own private key.
I apologize if something like this has already been asked.
Re: A few questions about encryption and decryption
a) There are thousands of different ways to encrypt, from a simple XOR cipher to something like the "Advanced Encryption Standard" (AES). The XOR is easy but less secure, while the AES is hard to implement but more secure. Look up these techniques for more info. b) The most secure place to keep the private key would be independent of the application - for instance in the user's head: when your app needs to decrypt they enter in the password.