In this paper, we present a way to think about the relative strength of security protocols using SoS, a lattice-theoretic representation of security strength. In particular, we discuss how the model can be used, present the TLS protocol as a compelling real world example, show how it is modeled, and then explain how lattice-theoretic properties can be used to evaluate security protocols. Categories and Subject Descriptors H.1 [Models and Principles]: Miscellaneous; D.4.8 [Software Engineering]: Performance--Measurements, Modeling and prediction General Terms Security Keywords Cryptographic protocols, Relative strength, Lattice, Comparison