An Optimistic Fair Exchange (OFE) protocol is a good way for two parties to exchange their digital items in a fair way such that at the end of the protocol execution, both of them receive their items or none of them receive anything. In an OFE protocol there is a semi-trusted third party, named arbitrator, which involves in the protocol if it is necessary. But there is a security problem when a...

an efficient protocol for the selective oxidation of primary alcohols to aldehydes withh5io6/v2o5 in ionic liquid [bmpy][pf6] has been developed. high yields of the products, mildreaction conditions and simple experimental procedure make this protocol complementary tothe existing methods. the catalyst can be reused for several times without obvious loss of thecatalytic activity.

Regarding the false negative results of culdocentesis, it is believed that the protocol of B-hCG, sonography, D&C and free use of laparoscopy gives more reliable information to the physician than the protocol of B-hCG, sonography and culdocentesis. We used the former protocol on 50 patients suspected of having ectopic pregnancy. The most common diagnoses were EP (48%) and PID (16%), respec...

many performance evaluations for ieee 802.11distributed coordination function (dcf) have been previouslyreported in the literature. some of them have clearly indicatedthat 802.11 mac protocol has poor performance in multi-hopwireless ad hoc networks due to exposed and hidden nodeproblems. although rts/cts transmission scheme mitigatesthese phenomena, it has not been successful in thoroughlyomit...

abstract: nowadays due to developing the information technology, buildings are equipped to this technology in order to reduce energy consumption and make more convenient for inhabitants. the popularity of smart home has been increasing greatly in recent years due to much higher affordability and simplicity through android smartphone connectivity. this paper prepares a review of smart home and h...

The widespread use of wireless cellular networks has made security an ever increasing concern. GSM is the most popular wireless cellular standard, but security is an issue. The most critical weakness in the GSM protocol is the use of one-way entity authentication, i.e., only the mobile station is authenticated by the network. This creates many security problems including vulnerability against m...

Time Saving and energy consumption has become a vital issue that attracts the attention of researchers in Underwater Wireless Sensor Networks (UWSNs) fields. According to that, there is a strong need to improve MAC protocols performance in UWSNs, particularly enhancing the effectiveness of ALOHA Protocol. In this paper, a time-saving Aloha protocol with slotted carrier sense proposed which we c...

Search protocols are among the main applications of RFID systems. Since a search protocol should be able to locate a certain tag among many tags, not only it should be secure against RFID threats but also it should be affordable. In this article, an RFID-based search protocol will be presented. We use an encryption technique that is referred to as authenticated encryption in order to boost the ...