A note on a provable secure encryption scheme

A Cramer-Shoup scheme was modified in a variant way.The major advantage with respect to Kurosawa-Desmedt scheme is that it saves a key parameter and produces shorter ciphertext.The proof of security shows that our scheme can be instantiated with any computational secure key derivation and message authentication functions.Thus it extends the applicability of the Kurosawa-Desmedt scheme and improves its effciency.     

‘Tool port’ to ‘landlord port’: a game theory approach to analyse gains from governance model transformation

This study investigates potential port users’ surplus and terminal operators’ profits due to transforming port governance from the ‘tool port’ model to the ‘landlord port’ model. Although the landlord port model is one of the most adopted and successful port governance models, many ports still operate under other models. Chittagong Port, the largest port in Bangladesh, currently operates under the tool port model, while the country’s second-largest port, Mongla Port, operates under the service port model. Chittagong Port is currently facing many challenges, including capacity expansion and renovation of port facilities. Therefore, we form four hypothetical situations for port governance model transformation, assuming that Chittagong Port will transform to the landlord port model but that Mongla Port will run under the existing governance model. Estimating a Bertrand game model, we present a cost-benefit analysis for port users and terminal operators (or port authorities) in hypothetical game situations. The results reveal that privatising one of the container terminals under a landlord setting is the most profitable scenario for Chittagong Port Authority, but privatising all terminals of Chittagong Port yields the highest users’ surplus. However, privatising two of the terminals while they cooperate yields the lowest users’ surplus.     

Efficient Protocol-Proving Algorithm Based on Improved Authentication Tests

A new efficient protocol-proving algorithm was proposed for verifying security protocols. This algorithm is based on the improved authentication tests model, which enhances the original model by formalizing the message reply attack. With exact causal dependency relations between messages in this model, the protocol-proving algorithm can avoid the state explosion caused by asynchronous. In order to get the straight proof of security protocols, three authentication theorems are exploited for evaluating the agreement and distinction properties. When the algorithm terminates, it outputs either the proof results or the potential flaws of the security protocol. The experiment shows that the protocol-proving algorithm can detect the type flaw attack on Neuman-Stubblebine protocol, and prove the correctness of NSL protocol by exploring only 10 states.