This paper examines the suitability and use of runtime verification as means for monitoring security protocols and their properties. In particular, we employ the runtime verification framework introduced in [5] to monitor complex, history-based security-properties of the SSL-protocol. We give a detailed account of the methodology, compare its formal expressiveness to prior art, and describe its application to an open-source Java-implementation of the SSLprotocol. In particular, we show how one can make use of runtime verification to dynamically enforce that assumptions on the crypto-protocol implementations (that are commonly made when statically verifying crypto-protocol specifications against security requirements) are actually satisfied in a given protocol implementation at runtime. Our analysis of these properties shows that some important runtime correctness properties of the SSL-protocol exceed the commonly used class of safety properties, and as such also the expressiveness of ...