How to encrypt/decrypt a file in Java?

Question

I am writing a Java application which can \"encrypt\" and consequently \"decrypt\" whatever binary file.

I am just a beginner in the \"cryptography\" area so I would

Answer 1

A really simple way to use a password to encrypt is to use XOR, here is some pseudo code

for(byte in file)
{
    Byte newByte = byte ^ (byte) password[i];
    outputFile.write(newByte);
    i = (i + 1) password.length();
}

This is based on the identity that (x XOR y) XOR y = x, all you need to do is encrypt/decrypt with the same password.