Researches in Information Security Research Lab Mainly, Sensor and Ad Hoc Network Security

1. Researches in Information Security Research LabMainly, Sensor and Ad Hoc Network Security DaeHun Nyang ISRL, InHa Univ.

2. Ad Hoc Network Security: Threshold Crypto. • Devise an Efficient Threshold cryptography • Threshold Schnorr Digital Signature[NK05] • Running time of URSA is probabilistic and slow. Also, it turns out not to be secure. • Provably as secure as Schnorr’s • Published in KIISC Journal • Preparing to submit to some other international conference or journal [URSA] IEEE/ACM TRANSACTIONS ON NETWORKING, VOL. 12, NO. 6, DECEMBER 2004 1049, URSA: Ubiquitous and Robust Access Control for Mobile Ad Hoc Networks, Haiyun Luo, Jiejun Kong, Petros Zerfos, Songwu Lu, Lixia Zhang

3. Ad Hoc Network Security • Distributed CA • For large scale ad hoc network, a whole network is divided into some well defined sub structure. • For issuing certificates, we use extensively locality. • No need to use certificate chain. • To justify the idea, ns-2 simulation result is shown. • Reputation compensation protocol • There exists some bias among reputations, and thus, reputation must be compensated for nodes in hostile environment. • NS-2 simulation result is shown.

4. Converting balanced password authentication into augmented one • Using ZKIP-based identification, a generic method to convert a balanced password authentication protocol into an augmented one. • Advantage • Easy to obtain augmented protocol from balanced one. Note that augmented protocol is much more strong against password file compromise. • Can be efficient depending on the underlying ZKIP • Also, promising result can be seen. • Status • Have failed to be published since ??. • Submitted to an international journal(JCST). • Now, co working with Kwon.

5. Pre-key distribution for SN • Hierarchical Grid Based Pre-Key distribution Scheme. • Key generation protocol is based on bivarate polynomial, but the grid looks very different from Liu-Ning’s. • The grid from some ad hoc routing protocol which is based on GPS. We reduce the expansion factor to 2. • Our grid is more appropriate for deployment considering real geometric terrain. • Also, the required computation is proportional to the degree of security. • Compromising some node does not affect the whole network. • Status • Co working with Aziz. • Submitted to EWSN05(European Wireless Sensor Network)

6. Public key authentication for SN • Motivated by reading [DWN05]. • Not using certificate to verify a public key. They use Merkle’s hash tree. • My idea was using Liu-Ning’s grid to organize Merkle’s hash tree in a novel way. It beats [DWN05] in terms of memory requirement and also communication overhead. • It mimics certificate chain by well organizing the two dimensional merkle tree. Surely, it can be expanded to n-dimensional tree. • Status • Co working with Prof. Jeong at SKHU. • Plan to submit it to MOBIHOC05 of which deadline is 4th of Dec. [DWN05] Mobihoc05, An Efficient Scheme for authenticating public Keys in SN by Du, Wang, Ning

7. RFID Security • Ownership tag • Using Selective collision in the mac layer, we achieve some level of privacy by intervening so called, “Ownership Tag”. • Co work with Park and Kang • Accepted to UISW 05. • RFID authentication protocol • Strong against DoS attack. • Accepted to ESAS05(European Sensor and Ad hoc network Security) • Co work with Kang

8. Security in Biometrics • Template is too sensitive to be used in clear form. It cannot be canceled. • Store the encrypted template? -> whenever matching occurs, decryption of template must be accompanied. • If we can perform the matching algorithm btw transformed templates and transformed image captured, we can solve the problem. • To do this, we introduce some transform that does not affect the matching process. • But it introduces intervention of user by submitting his/her password. -> Actually the memorization of password can be alleviated if we use another scenarios. • Co working with Kang. • Accepted to IWBRS 05.

9. Nowadays… • I’m interested in some new way to authenticate something such as public key, id, etc not using cryptographic method. • Lee(PhD Student) is now working on that. More precisely, he’s working one authentication under that framework. And I’m developing the framework itself. • Through series of seminars at this meeting, I will show the progress..