Security is a major concern is today's online world. As online activities become increasingly sensitive, service providers rely on security protocols to ensure confidentiality, integrity and authentication of their users and data. Greater assurance is provided when these protocols are verified to be correct. Strand Spaces is a method to formally analyze security protocols. The arguments are based on the messages being transmitted and received while assuming that the underlying cryptographic primitives are secure. This thesis demonstrates that the protocols Luau, pwdArmor and Kiwi are secure using Strand Spaces methodology.