Secure electronic communication relies on cryptography. Even with perfect encryption, communication may be compromised without effective security protocols for key exchange, authentication, etc. We are now seeing proliferation of large secure environments characterized by high volume, encrypted traffic between principals, facilitated by Public Key Infrastructures (PKI). PKIs are dependent on se...

We revise existing type-based analyses of security protocols bydevising a core type system for secrecy, integrity and authentication inthe setting of spi-calculus processes. These fundamental security proper-ties are usually studied independently. Our exercise of considering all ofthem in a uniform framework is interesting under different perspectives:(i) it provides a gener...

Real world protocols often involve human choices that depend on incentives, including when they fail and require fail-safe or fail-deadly mechanisms. We look at three example systems (the EMV protocol, consensus in cryptocurrencies, and Tor) in this context, paying particular attention to the role that incentives play in fail-safe and faildeadly situations. We argue that incentives should expli...

Many security protocols are built as the composition of an applicationlayer protocol and a secure transport protocol, such as TLS. There are many approaches to proving the correctness of such protocols. One popular approach is verification by abstraction, in which the correctness of the application-layer protocol is proven under the assumption that the transport layer satisfies certain properti...

In the field of security protocol analysis, a class of automated methods relies upon the use of symbolic techniques. We illustrate this approach by focusing on one such method. We outline the underlying protocol model, the concept of symbolic execution and the resulting verification method. We then discuss the benefits of the symbolic approach when contrasted with traditional methods baded on f...

A correct security protocol should satisfy four requirements: no-intrusion, authenticity, freshness, and secrecy. We divide the four requirements into two groups (one for no-intrusion, authenticity, and freshness and the other for secrecy). For the former we use the message-exchange forms and for the latter, we use the p-knows and n-knows information that is inferred from a latest topological o...

Security protocols use cryptography to set up private communication channels on an insecure network. Many protocols contain flaws, and because security goals are seldom specified in detail, we cannot be certain what constitutes a flaw. Thanks to recent work by a number of researchers, security protocols can now be analyzed formally. The paper outlines the problem area, emphasizing the notion of...

An agent-based model of interpersonal trust is used to develop information sharing security protocols in the spirit of soft security. We demonstrate that availability information can be balanced against security breaches. Our protocols are simple, malleable, and scalable. Index Terms – Security protocols, soft security, agents