Key's random art image is mostly black

Question

I have generated an SSH key on Ubuntu 10.04 with

 ssh-keygen -t rsa -C "[email protected]"

and the key's random art image comes out mostly empty (modified slightly):

+--[ RSA 2048]----+
|                 |
|                 |
|                 |
|                 |
|        D        |
|      s.J        |
|       Bv.++=    |
|      =ooo.=o+   |
|     c .+*.+o.   |
+-----------------+

Does that indicate an issue with the random number generator?

Answer 1

No.

The "random art" image is created by a random walk through the image area, using the key's fingerprint as the sequence of moves to make. The fingerprint is short enough that the art can never cover more than about 40% of the image.

An analysis of the art and some attempts at attacks on it are available in the paper "The Drunken Bishop".