2567756 will become 4789978
For a more complex encryption you can use a +2-1+2. What that mean is the first digit will be increases by 2, the middle digits will be decreased by 1, and the last digit increases by 2. For example:
2567756 will become 4456648
You can be creative with your encryption but you need to remember your method. If you forget your encryption the numbers will be useless. I suggest encrypting all account numbers and social security numbers. If it is important enough for you to encrypt it should probably hand write it in.
You can directly download the template from HERE.