Using Simmel's article "The Sociology of Secrecy and of Secret Societies' as a point of departure (Simmel 1906: 441–498), this chapter examines selected aspects of the social scientific field of secrecy. As Simmel conceptualized it, the secret is a central means for information control in contemporary society. A brief survey of Simmel's writing on secrecy leads to a first conclusion that Simmel's impact was rather diffuse at best. As is consistent with his approach, Simmel offers sensitizing principles, which a contemporary researcher might take as groundwork for future research. Here as elsewhere (Marx/Muschert 2007: 375–395), we argue that what is needed is a sociology of information framework for the study of information flows, restrictions and blockages in contemporary society. We outline the framework and some related concepts connected to secrecy: including, publicity, privacy, secrecy, the paradoxes of information, and the value of information. We conclude with a suggestion about how Simmel's writing on secrecy might be usefully connected with his more famous piece on money ([1900]). By considering information as an object of value subject to principles of exchange, we suggest a number of propositions which might serve future research within a sociology of information framework.