## CryptoDB

### Atefeh Mashatan

#### Publications

Year
Venue
Title
2012
CRYPTO
2008
EPRINT
We examine the problem of message and entity recognition in the context of ad hoc networks. We review the definitions and the security model described in the literature and examine previous recognition protocols described in ABCLMN98, HWGW05, LZWW05, M03, and WW03. We prove that there is a one to one correspondence between non-interactive message recognition protocols and digital signature schemes. Hence, we concentrate on designing interactive recognition protocols. We look at LZWW05 in more detail and suggest a variant to overcome a certain shortcoming. In particular, in case of communication failure or adversarial disruption, this protocol is not equipped with a practical resynchronization process and can fail to resume. We propose a variant of this protocol which is equipped with a resynchronization technique that allows users to resynchronize whenever they wish or when they suspect an intrusion.
2008
EPRINT
We propose a message recognition protocol which is suitable for ad hoc pervasive networks without the use of hash chains. Hence, we no longer require the sensor motes to save values of a hash chain in their memories. This relaxes the memory requirements. Moreover, we do not need to fix the total number of times the protocol can be executed which implies a desired flexibility in this regard. Furthermore, our protocol is secure without having to consider families of assumptions that depend on the number of sessions the protocol is executed. Hence, the security does not weaken as the protocol is executed over time. Last but not least, we provide a practical procedure for resynchronization in case of any adversarial disruption or communication failure.
2007
EPRINT
We propose an interactive message authentication protocol (IMAP) using two channels: an insecure broadband channel and an authenticated narrow-band channel. We consider the problem in the context of ad hoc networks, where it is assumed that there is neither a secret key shared among the two parties, nor a public-key infrastructure in place. The security of our IMAP is based on the existence of Interactive-Collision Resistant (ICR) hash functions, a new notion of hash function security. Our IMAP is based on the computational assumption that ICR hash functions exist. It performs better than message authentication protocols that are based on computational assumptions. That is, while achieving the same level of security, the amount of information sent over the authenticated channel in our IMAP is smaller than the most secure IMAP and Non-interactive Message Authentication Protocol (NIMAP) in the literature. In other words, if we send the same amount of information over the authenticated channel, we can allow much stronger adversaries compared to the existing protocols in the literature. Moreover, our IMAP benefits from a simple structure and works under fewer security assumptions compared to other IMAPs in the literature. The efficient and easy-to-use structure of our IMAP makes it very practical in real world ad hoc network scenarios.
2006
EPRINT
We consider the problem of non-interactive message authentication using two channels: an insecure broadband channel and an authenticated narrow-band channel. This problem has been considered in the context of ad hoc networks, where it is assumed that there is neither a secret key shared among the two parties, nor a public-key infrastructure in place. We present a formal model for protocols of this type, along with a new protocol which is as efficient as the best previous protocols. The security of our protocol is based on a new property of hash functions that we introduce, which we name hybrid-collision resistance''.

#### Coauthors

Asli Bay (1)
Douglas R. Stinson (4)
Serge Vaudenay (1)