CallRank: Combating SPIT using call duration, social networks and global reputation

The growing popularity of IP telephony systems has made them attractive targets for spammers. Voice call spam, also known as Spam over Internet Telephony (SPIT), is potentially a more serious problem than email spam because of the real time processing requirements of voice packets. We explore a novel mechanism that uses duration of calls between users to combat SPIT. CallRank, the scheme proposed by us, uses call duration to establish social network linkages and global reputations for callers, based on which call recipients can decide whether the caller is legitimate or not. CallRank has been implemented within a VoIP system simulation and our results show that we are able to achieve a false negative rate of 10 % and a false positive rate of 3% even in the presence of a significant fraction of spammers

A Patient-centric, Attribute-based, Source-verifiable Framework for Health Record Sharing

The storage of health records in electronic format, and the wide-spread sharing of these records among different health care providers, have enormous potential benefits to the U.S. healthcare system. These benefits include both improving the quality of health care delivered to patients and reducing the costs of delivering that care. However, maintaining the security of electronic health record systems and the privacy of the information they contain is paramount to ensure that patients have confidence in the use of such systems. In this paper, we propose a framework for electronic health record sharing that is patient centric, i.e. it provides patients with substantial control over how their information is shared and with whom; provides for verifiability of original sources of health information and the integrity of the data; and permits fine-grained decisions about when data can be shared based on the use of attribute-based techniques for authorization and access control. We present the architecture of the framework, describe a prototype system we have built based on it, and demonstrate its use within a scenario involving emergency responders' access to health record information

Using multicast communication for resource finding in distributed systems

Issued as final reportProject no. C-36-651 (includes subproject no. C-36-616