CRS generation for NIZK proof I am interested in learning more about NIZK proofs in the CRS model.

The CRS must be random but 'trusted' by all parties.

How does these data get generated both in theory and in practice?
The CRS must be generated in some trusted manner. One could use a secure coin tossing protocol involving a number of parties, and this would be fine as long as a majority of the parties are honest. 

One could also apply a hash function to the New York Times of January 1st 2000 (or any other date) and use the result, although this would need a random oracle assumption.