[Dev-C++] Simple encryption/obfuscation

[Ed C. <em...@to...>]

Hello all,

I need help on an algorithm. I need to accept username/password =
combinations
on the client side of a client-server app, store those on the client =
side,
and "decrypt" them again without user input, using only the stored =
strings.
Think the "remember my password" function in MS Outlook, IE, etc.

Ideally, I would like to do this:
On first run:
1) Accept email address
2) Accept username & password pairs
3) "Encrypt" username/password pairs with email address + some
machine-dependent data as a key
4) Write these encrypted pairs and the email address to a text file

On future runs:
1) Read the encrypted pairs
2) "Decrypt" them
3) Do stuff.

The best idea I have now is some block-and-bit chunking and shifting - =
break
the string to encrypt into variable-length chunks, shuffle, reassemble, =
bit
rotate, repeat. The "decrypt" would simply reverse the process. My =
concern
is that anybody who knows the algorithm will be able to reverse it quite
easily, given access to the text file.

Any help is appreciated!

-Ed