Java encyption for text files

Hi all,

for my project I've created a simple java game which has save/load functions. I plan for my save to pretty much just copy loads of variables from the game into a text file which can be read from the load.

However if someone accesses the text file then they can easily change the values which isn't really the point of save/load.

Is there any way to encrypt the text file or anything (it can be really simple) or any ideas of the best way to keep a basic security for the text file.

Thanks in advance.

If you asked Google this question you would probably get any amount of information about techniques that other people actually use.

Perhaps you did better to ask here! Where you get a human response: concerned as much about you as about the encryption task. My response would have to be "How would you do this by hand?" In other words if you had some textual information that you accepted would be physically accessible to anyone, how would you encrypt it so that it would be unreadable? (Think of a notebook with passwords in it, or a diary)

Once you have some plan you could post it here for people to find fault with (and, thereby improve). When (and only when) you have plan that you're happy with you can start implementing it with code - at which point you might have specific questions to ask.

Just my 2c.

You can encrypt, but probably a much simpler method that would be good enough, would be to simply use Object Serialization. It'll save a ton of work with regards to writing and reading variables (it skips that all together) and it produces a binary file which will be largely illegible. Might be much easier to get into than encryption.

Hi everyone,

Thanks for your replies.

The only problem is that for my project were not allowed to use the serialization interface in my project (im guessing as it saves alot of trouble and they want us to show a solution by ourselves).

I'm pretty new to java so might be bad but heres what I thought:

As I've got to write save/load without the help of javas serialization, I was going to have a folder which is called saved games or something.
Then I was going to create a new class called "GameState" which is essentially every variable I'd need to save. Then for each class based on the game I was going to copy these onto one line of the file. (each line would be the variables of one of the classes).

So for example say I have three classes' variables which need to be saved, it will be all be in one text file but on three lines. So pretty much on every saved game there will be one text file created.

Then when loads made I can read the lines one by one and load it back into the appriopiate objects of the three classes.

My other idea was to put every saved game on one line (so theres one text file for all saved games, but I think it would be really hard to write back into the objects when load is called as there are so many variables to be saved.

Going back to the possible encryption I was thinking when the lines are being created, before its written maybe instead of using encryption, I would maybe convert it to bytes or something thats hard to read by humans. I was talking to a course mate and they said that the security on the file can be very basic as long as values can't be changed easily so I thought maybe a encryption might be to much and maybe theres a simple way to do it.

Sorry I went onto the save/load but I'm sort of stuck on that aswel thought I'd see what people thought about it.

Might not work or be completely wrong but thats the easiest idea I can think of at the moment.

Please let me know what you think.

Thanks in advance

Seems to me you and 'newToJava3' are doing the same project. Have you been reading his page too? http://www.java-forums.org/new-java/...tml