185 research outputs found
Efficient and Low-Cost RFID Authentication Schemes
Security in passive resource-constrained Radio Frequency Identification
(RFID) tags is of much interest nowadays. Resistance against illegal tracking,
cloning, timing, and replay attacks are necessary for a secure RFID
authentication scheme. Reader authentication is also necessary to thwart any
illegal attempt to read the tags. With an objective to design a secure and
low-cost RFID authentication protocol, Gene Tsudik proposed a timestamp-based
protocol using symmetric keys, named YA-TRAP*. Although YA-TRAP* achieves its
target security properties, it is susceptible to timing attacks, where the
timestamp to be sent by the reader to the tag can be freely selected by an
adversary. Moreover, in YA-TRAP*, reader authentication is not provided, and a
tag can become inoperative after exceeding its pre-stored threshold timestamp
value. In this paper, we propose two mutual RFID authentication protocols that
aim to improve YA-TRAP* by preventing timing attack, and by providing reader
authentication. Also, a tag is allowed to refresh its pre-stored threshold
value in our protocols, so that it does not become inoperative after exceeding
the threshold. Our protocols also achieve other security properties like
forward security, resistance against cloning, replay, and tracking attacks.
Moreover, the computation and communication costs are kept as low as possible
for the tags. It is important to keep the communication cost as low as possible
when many tags are authenticated in batch-mode. By introducing aggregate
function for the reader-to-server communication, the communication cost is
reduced. We also discuss different possible applications of our protocols. Our
protocols thus capture more security properties and more efficiency than
YA-TRAP*. Finally, we show that our protocols can be implemented using the
current standard low-cost RFID infrastructures.Comment: 21 pages, Journal of Wireless Mobile Networks, Ubiquitous Computing,
and Dependable Applications (JoWUA), Vol 2, No 3, pp. 4-25, 201
Efficient Multi-Party Contact Tracing
Since the beginning of the Covid-19 Pandemic, many Countries adopted Contact Tracing Apps as an automatic way to trace if someone has been in contact with a Covid-19 patient. However, most existing solutions consider two party settings only. Since many people meet at the same time in real-life scenarios, one cannot extend current schemes to multi-party settings because they will not scale well and burden the device. In this paper, we propose a new contact tracing protocol that works in a multi-party setting. We evaluate our scheme to show its efficiency.M. de Goyon, A. Miyaji and Y. Tian, "Efficient Multi-Party Contact Tracing," in 2021 Ninth International Symposium on Computing and Networking (CANDAR), Matsue, Japan, 2021 pp. 10-18. doi: 10.1109/CANDAR53791.2021.00010
PNB-focused Differential Cryptanalysis of ChaCha Stream Cipher
This study focuses on differential cryptanalysis of the ChaCha stream cipher. In the conventional approach, an adversary first searches for an input/output differential pair with the highest differential bias and then analyzes the probabilistic neutral bits (PNB) based on the obtained input/output differential pair. However, although the time and data complexities for the attack can be estimated by the differential bias and PNB obtained by this approach, the combination of the differential bias and PNB is not always optimal. In addition, the existing studies have not performed a comprehensive analysis of the PNB; thus, they have not provided an upper bound on the number of rounds required for a differential attack that uses a single-bit truncated differential to be successful. To address these limitations, we propose a PNB-focused differential attack on reduced-round ChaCha by first comprehensively analyzing the PNB for all possible single-bit truncated output differences and then searching for the input/output differential pair with the highest differential bias based on the obtained PNB. The best existing attack on ChaCha, proposed by Beierle et al. at CRYPTO 2020, works on up to 7 rounds, whereas the most extended attack we observed works on up to 7.25 rounds using the proposed PNB-focused approach. The time complexity, data complexity, and success probability of the proposed attack are , , and 0.5, respectively. Although the proposed attack is less efficient than a brute force attack, it is the first dedicated attack on the target and provides both a baseline and useful components (i.e., differential bias and PNB) for improved attacks
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