Security is a critical and vital task in wireless sensor networks (WSNs), therefore different key management systems have been proposed, many of which are based on symmetric cryptography. Such systems are very energy efficient, but they lack some other desirable characteristics. On the other hand, systems based on public key cryptography (PKC) have those desirable characteristics, but they cons...

The private keys used in a PKI are its most important asset. Protect these keys from unauthorised use or disclosure is essential to secure a PKI. Relying parties need assurances that the private key used to sign their certificates is controlled and managed following pre-defined statement policy. Hardware Security Modules (HSM) offer physical and logical protection and should be considered for a...

Problem statement: Key management is an important cryptographic technique for providing security in a dynamic environment of sensor networks. To provide a secure communication among a group of sensor nodes keys should established in an efficient manner. We introduced an efficient and dynamic key management system for dynamic sensor networks. Approach: We pre deployed some of the keying material...

Background and purpose: To determine an appropriate financial model for the health system of Iran, several studies have been conducted. But it seems that these studies were not comprehensive and further investigation is required. So to design a valid and enforceable mechanism, the study of policy interventions will be considered through consensus of all stakeholders. This investigation was done...

Updatable oblivious key management system (UOKMS) has been widely applied in reality to protect outsourced data confidentiality. We demonstrate that existing UOKMS fails prevent users’ private information from being leaked. show an adversary can impersonate any user access her/his sensitive UOKMS, and this problem is further exacerbated by the collusion between two entities (i.e., a server clou...