I came across the notion of Common Reference String (CRS) model while reading this paper on a protocol for UC Oblivious Transfer: https://eprint.iacr.org/2007/348.pdf
I did some research and it seems to me that the CRS model is just some way to model hash functions: What are alternatives to the random oracle model for modelling hash functions?
My questions are:
What is exactly the CRS model?
What are the main differences, comparing to the Random Oracle Model (ROM)?
What are the advantages and disadvantages of using the CRS model instead of using the ROM?
Thank you in advance