Creating a Barcode

Create a new document, 1000x1000 pixels, white background.

Make a new layer and with the rectangle marquee tool make a rectangle. Fill it with white.

Go to Filter > Noise > Add noise. Add about 50-60% amount, gaussian and monochromatic.

With the selection still on, go to Filter > Pixelate > Crystalize and give it an amount of 10 to the cell size.

After doing so, double click on the noise layer to enter the layer style options. Now drag the slider like in my example to get rid of the grey points.

Now deselect (CTRL+D) and go and select the "single row marquee tool" and click on the middle of the selection like in my example.

Press CTRL+T to enter the free transform mode. Drag from the center of the selection down and hit OK. You'll end up with something like this:

Now delete the other noise points that are left in order to remain only the lines. Here it is:

Now duplicate the layer several times and move them a little to the left or to the right.

Now select all the layers but the background and press CTRL+E to merge them all. On this layer make a rectangular selection and press DELETE. In this blank field type a random number. You're done: