Advanced Data Protection

You can combine the data-duplication and obfuscation techniques for added security. Ideally you should use a different XOR hash for the score and scoreCheck values. That will make it harder for a cheater to notice, otherwise the memory addresses will contain matching values and make it easier to find your checksum.

Example Code

Android/Java

private int xorCode = 12345; // USE A DIFFERENT XOR VALUE THAN THIS!
private int scoreCheckXorCode = 54321; // USE A DIFFERENT XOR VALUE THAN THIS!
private int score = 0;
private int scoreCheck = 0;

// Make sure to xor the initial values
@Override
private void onCreate(Bundle savedInstanceState) {
    score = score ^ xorCode;
    scoreCheck = scoreCheck ^ scoreCheckXorCode;
}

// Functions and mutators should xor the value before using it, and xor the value again before the function exits
private void addScore(int increase) {
    score ^= xorCode;
    score += increase;
    score ^= xorCode;
    scoreCheck ^= scoreCheckXorCode;
    scoreCheck += increase;
    scoreCheck ^= scoreCheckXorCode;
}

// Confirms that the score is valid.
private boolean confirmScoreValidity() {
    return (score ^ xorCode) == (scoreCheck ^ scoreCheckXorCode);
}