Control Games

Datum

What is it?

Datum is a little program that can encrypt a picture, so it's not recognizable any more, and restore it after a certain amount of time.
It's best used with a number padlock.

It's written in Java, so it'll work on any platform (Windows, Mac, Linux).

How to use it

Change the combination of your number padlock without looking at it.
Take a photo of the new combination still without looking at it. This is the difficult step! The photo must be readable but you must not read it. You'll have to exercise several times (still looking at the combination for exercise purposes) until you're really sure.
The picture file must be in one of the formats .jpg, .png or .jpeg. Use an automatic conversion program if needed.
Scramble the combination.
Put the cigarettes or chocolates in a box and lock it with the padlock.
If not yet done, connect your camera to your computer.
Start Datum and fill in the fields defining the duration.
Click "encrypt", then select the picture file that's the photo of the combination.
That's it! When Datum is started, it checks regularly if it's time to restore your picture. Wait patiently!

Tips & tricks

Use a picture preview that's clear enough to see if the photo is OK, but too small to read the combination.
Alternatively, you may use a scanner to make the picture, or the room monitoring function of a webcam (takes a picture at regular intervals and stores it on your hard disk)
There are very small number safes (brand "Master" in France and Germany, to be found in DIY stores) to lock down a key.

Warnings and disclaimers

The original photo is deleted after encryption!
If there's a previously encrypted picture file next to the program, it will be deleted when you encrypt a new one. If you'd like to encrypt several pictures, create a directory with a copy of datum.jar for each of them.
There's no way to restore an encrypted picture before the date decided at encryption!
There's no way to restore the picture if you change even a single bit of the encrypted file, or if you delete it!
Newer versions of the program aren't able to decrypt pictures encrypted using a previous one! Always keep the program you used to encrypt along with the encrypted file.
Use at your own risk! The author declines any responsibility for the wanted or unwanted consequences of the use of the program.
Try out and exercise before real use!

Download and installation

Click here to download the .zip file.
Unzip it. It produces a single directory called "datum" containing a single file called "datum.jar".
Double-click datum.jar. If Java is properly installed on your machine, it will open a window.
If it doesn't, install or reinstall Java properly from java.sun.com. It's completely free. You need the standard Java Runtime Environment (JRE).
The user interface is straightforward. Have fun!
If you want to encrypt several pictures, just make several copies of the whole directory "datum" including datum.jar

Technical facts

To avoid cheating with the clock of your machine, the current date and time is taken from several official time servers in the internet. That's why you must be connected to internet when using Datum.

Future enhancements

An email function is already programmed (it automatically sends an email when it's time and the picture is restored), but it's disabled in this test version because it's a bit difficult to install and configure (you need to start the program indicating additional .jar files, and it needs a username and password for an SMTP server, like the program you use to write emails). If many users need it, I will enable it again.
Please feel free to use the feedback form below to suggest other new features and enhancements!