The following posts give an introduction to infrastructures and how to obtain these from global fields:
- The Discrete Logarithm Problem and Generalizations.
- One-dimensional Infrastructures.
- Interpreting One-dimensional Infrastructures as Groups: f-Representations.
- n-dimensional Infrastructures.
- How to Obtain Reduction Maps for n-dimensional Infrastructures.
- Obtaining Infrastructures from Global Fields.
See also my article on infrastructures at Wikipedia.