I study two privacy-preserving social network graphs to dis- close the types
of relationships of connecting edges and provide flexible multigrained access
control. To create such graphs, my schemes employ the concept of secretaries
and types of relationships. It is significantly more efficient than those that
using expensive cryptographic primitives. I also show how these schemes can be
used for multigrained access control with various options. In addition, I
describe how much these schemes are resilient to infer the types of connecting
edges