Combine sugar, water, vinegar and salt in a small saucepan

Bring to a boil, stirring until sugar dissolves

Reduce heat and simmer until syrupy, but do not allow sauce to caramelize, about 15 minutes

Remove from heat and stir in chili paste with garlic

Cool

Stir in lime juice, fish sauce and cilantro. Thread the shrimp on the kebob skewers

Brush with sauce and rotate for 15 minutes or until shrimp are cooked through

Serve with remaining sauce for dipping.