A relational algebraic approach to protocol verification

Protocol verification using database technology

“…We provide only a brief overview of the relational algebra approach to protocol verification originally described in [18]; the reader is referred to the original paper for a more complete and formal description. As in [ 181, we illustrate the approach using the example of the simple connection establishment protocol presented in [26].…”

“…Step 2: Create the system transition relation for a sreadq system [18] -defined to be a system in which only one message is allowed to be transmitted at a time. In a steady system, no message may be sent until the previous message is received, and processes do not receive messages simultaneously.…”

“…Step 3: In this step, we begin the transformation of the steady transition relation J into the global-state transition relation G. Reference [18] describes this part of the transformation as the result of the union of four separate joins of a relation comprising a single tuple on projections of restrictions of relation J; the joins in this step can be replaced by an equivalent set of more easily computed single scan selection and attribute append operations. This process separates the effects of message transmission by A, message reception by B, message transmission by B, and message reception by A, on global-state transitions and introduces the concept of channels for messages sent from A to B (A-TO-B) and from B to A (B-TO-A).…”

“…Using a modified version of the REPROVER verification software described in [ 171, we verified four relatively small protocols: the simple connection establishment protocol described in Section II, the example process interaction protocol from [18], [27], X.21 [26], and the binary synchronous (bisynch) protocol [lo]. Table V illustrates the cardinality of the Z, J, and G relations for each protocol; the largest, the binary synchronous protocol, has 354 states in its global-state transition relation G. Table V shows a consistent pattern across the four protocols studied.…”

A layered communication system generator

“…The approaches to protocol validation are mainly classified into two categories: perturbation analysis [5, 81 and the relational algebraic approach [9]. The perturbation analysis cannot systematically express the validation procedure.…”