[Cryptography] New attacks on discrete logs?

[Bear]

On Thu, 2014-05-22 at 11:14 +0200, Hanno Böck wrote:

> Okay, to clear this up:
> There's been an algorithm improvement on discrete logs in so-called
> finite fields with small characteristics. However, it's not that "new",
> it's from early 2013, it just has been presented at the eurocrypt
> conference recently.

Would anyone like to clarify what exactly they mean by 
"small" and "large" characteristic here?  Please?

Bear