How long were Jews kept living in Ghettos and in what year were they allowed to purchase last names?

What country was responsible for this move to allow Jews to have last names, and in what era? And how was the charges for the various names determined other than those reflecting the trade of these people. Was Goldsmith, a double name, more expensive than Gold or Silverman or blacksmith and why? What were the rules surrounding this name change/addition policy?

How long were Jews kept living in Ghettos and in what year were they allowed to purchase last names?
I didnt know that Jews had to purchase last names. How much can I get for a last name?
Reply:Don't bother going to the above links, they're 'Hate sites' the poster is obviously a Nazi. So far she has only been interested in questions concerning Jews [see her profile] and her only dubious contribution on all, is to post the same old hate sites. She has no mind of her own!