Dota 2is one popular multiplayer online battle arena game, and it holds the grandest e-sports tournament in the world—The International. However, smurfs and boosters are plaguing the game, causing a continuous decline in the player count. Smurfs are skilled players who stomp less experienced players, while boosters are paid to improve players’ rank. At this stage, the developers have brought updates on smurf detection based on players’ complaints, where smurf accounts are likely to be prevented from entering the game. This article proposes a smurf or booster detection among the players by profiling and identifying them based on statistical differences in features. Initially, we created a dataset with player data collected from the OpenDota API. Then, K-means was used to group and profile the players. Subsequently, the interquartile range method was applied to the high-performing players to identify the smurfs or boosters. We then invited threeDota 2game experts to review the resulting profiles. A 95% accuracy score was achieved using majority voting. The methodology proposed in this article can be implemented in theDota 2to detect smurfs or boosters automatically. The findings in this article shall contribute to prolonging the game's life span.

SABER is a round 3 candidate in the NIST Post-Quantum Cryptography Standardization process. Polynomial convolution is one of the most computationally intensive operation in Saber Key Encapsulation Mechanism, that can be performed through widely explored algorithms like the schoolbook polynomial multiplication algorithm (SPMA) and Number Theoretic Transform (NTT). While SPMA multiplier has a slow latency performance, the NTT-based multiplier usually requires large hardware. In this work, we propose KaratSaber, an optimized Karatsuba polynomial multiplier architecture with a balanced hardware efficiency (throughput-per-slice, TPS) compared to NTT and SPMA based designs. KaratSaber employs several techniques for an efficient design: a parallel grid input technique for efficient pre-processing stage in Karatsuba-based polynomial multiplier, a novel instruction code result-mapping technique catering the negacyclic operations improves the post-processing stage efficiency, a double multiplicand shifter-based multiplier doubles the throughput at the multiplication stage. Combining these three techniques, the proposed KaratSaber architecture is 7.47 × faster compared to the state-of-the-art SPMA Saber architecture at the expense of 4.96 × additional hardware resources; making KaratSaber 46.04% more area-time efficient. When compared to LWRPro, a recent Karatsuba Saber architecture, KaratSaber architecture achieves a 2.11 × higher throughput by only utilizing 1.92 × additional hardware; thus gaining a 10.44% improvement in area-time efficiency.

Biometric cryptosystems present a promising avenue for secure authentication; however, the efficiency and security of such systems can be hindered by errors in biometric data. To address this challenge, existing systems employ error-correction codes, but often fail to consider the distribution of biometric sources, potentially leading to an underestimation of the system’s security. In response to this issue, we propose a novel algorithm pair, designated as ENCODE and DECODE, which facilitates direct codeword generation from biometric samples. Our approach accounts for the distribution of biometric sources, thereby providing a more accurate estimation of system security compared to traditional methods. Our proposed algorithm pair generates codewords that maintain interpretability and are sensitive to the cosine distance between original biometric samples. This similarity metric is particularly well-suited for high-dimensional data analysis and enables a precise assessment of system performance. We have rigorously established the correctness of our algorithm pair, and empirical results illustrate its efficacy in tolerating distance between codewords while preserving accuracy in cosine distance-sensitive contexts. This approach has the potential to significantly improve the efficiency and security of biometric cryptosystems, rendering them more appropriate for daily cryptographic applications.

The key encapsulation mechanism (KEM) is an important cryptographic tool to protect communication in the Internet of Things (IoT). In the near future, classical algorithms used to construct KEMs, such as RSA and elliptic curve cryptography, will be vulnerable to attacks from quantum computers. Recently, Yamada et al. proposed the quasicyclic medium density parity check (QC-MDPC) KEM, which is considered one of the most advanced code-based cryptosystems to resist quantum attacks. In this article, an optimized implementation of QC-MDPC KEM for IoT applications is presented. Our main contributions are threefold: 1) the fastest QC-MDPC McEliece decryption in field-programmable gate array (FPGA); 2) the first QC-MDPC KEM implementation in FPGA; and 3) the first iteration count attack-resistant QC-MDPC decoder in FPGA. To improve the decryption speed, we introduce a novel customized rotation engine (CRE) and incorporated several recent techniques reported in the literature, including adaptive threshold and Hamming weight estimation. The best-achieved throughput in our implementation on Xilinx Virtex 7 FPGA is 12.7% faster than the state-of-the-art result reported by Heyse et al. The proposed CRE was then integrated with QC-MDPC KEM to produce a fast and secure KEM. Furthermore, to prevent timing attacks demonstrated recently, a constant-time implementation of the QC-MDPC McEliece decoder was presented.

Postquantum cryptography attracts a lot of attention from the research community recently due to the emergence threat from quantum computer toward the conventional cryptographic schemes. In view of that, NIST had initiated the standardization process in 2017. Bit flipping key encapsulation (BIKE) designed by Aragon et al. is one of the promising code-based schemes among the round-3 candidates. BIKE utilizes a quasi-cyclic medium density parity check (QC-MDPC) code and incorporates a few variants derived from the McEliece, Niederreiter, and Ouroboros schemes. In this article, we present efficient and constant time implementation of BIKEI and BIKE-III in field-programmable gate array (FPGA), which has the best area-time efficiency so far. We proposed modification to the original one-round bit flipping algorithm to achieve more area-time-efficient decoding in hardware, which achieved latency of 464.73 and 556.52 μs for BIKE-I and BIKE-III, respectively, in Virtex-7. A pipelined key encapsulation architecture is proposed to speedup the key encapsulation of BIKE-I and BIKE-III, achieving the latency of 146.47 and 153.25 μs on the same FPGA platform. Considering the Artix-7 FPGA platform, our combined key generation and encapsulation module for BIKE-I is also three more area-time efficient compared with the state-of-the-art BIKE-I implementation by Aragon et al.

Encryption is primarily used to ensure the confidentiality of information transmitted over an insecure wireless channel. However, an encrypted signal may be received with some errors due to noise and interference in the wireless channel. To alleviate these errors in the received encrypted signal, Zibideh and Matalgah proposed two different versions of key‐based coded permutation cipher (KBCPC) aimed to improve the error performance and security of the transmission in the wireless channel. These two versions were designed based on the modified data encryption standard (M‐DES) and provide different levels of security. This study presents a divide‐and‐conquer attack on both M‐DES and KBCPC by exploiting the function that extends the length of output. Their analysis shows that these two ciphers can only provide 56‐bit level of security instead of the claimed 136‐bit and 173.67‐bit level of security for different versions. The authors' analysis is further verified through experiments. More importantly, their attack can be easily adapted to other schemes with a different encryption design but the same coding technique used in M‐DES or KBCPC.

The MISTY1 block cipher has a 64‐bit block size, a 128‐bit master key, and a total of 8 rounds. It is an ISO international standard, a Japanese CRYPTREC‐recommended e‐government cipher, and a European NESSIE selected cipher. In this study, the authors show another cryptographic weakness of the full MISTY1 cipher: they describe four classes of weak keys of the full MISTY1 cipher for a related‐key amplified boomerang attack that has a data complexity of chosen plaintexts and a time complexity of encryptions under each class of weak keys. The result shows that the MISTY1 cipher can be distinguishable from an ideal cipher in terms of related‐key amplified boomerang cryptanalysis, and users should be very careful when using MISTY1 for a full security in relevant application situations.

Current network simulators abstract out wireless propagation models due to the high computation requirements for realistic modeling. As such, there is still a large gap between the results obtained from simulators and real world scenario. In this paper, we present a framework for improved path loss simulation built on top of an existing network simulation software, NS-3. Different from the conventional disk model, the proposed simulation also considers the diffraction loss computed using Epstein and Peterson’s model through the use of actual terrain elevation data to give an accurate estimate of path loss between a transmitter and a receiver. The drawback of high computation requirements is relaxed by offloading the computationally intensive components onto an inexpensive off-the-shelf parallel coprocessor, which is a NVIDIA GPU. Experiments are performed using actual terrain elevation data provided from United States Geological Survey. As compared to the conventional CPU architecture, the experimental result shows that a speedup of 20x to 42x is achieved by exploiting the parallel processing of GPU to compute the path loss between two nodes using terrain elevation data. The result shows that the path losses between two nodes are greatly affected by the terrain profile between these two nodes. Besides this, the result also suggests that the common strategy to place the transmitter in the highest position may not always work.

In this paper, we point out some faulty instantiations of threshold ring signatures (TRS) based on the threshold proof-of-knowledge (TPoK) protocol. Although a TRS can be regarded as the non-interactive version of the TPoK, the computational domains of the variables should be carefully chosen. We show that by choosing some inappropriate domains, two such instantiations suffer from forgery and anonymity attacks. Our attacks rely on algebraic techniques which involve solving some particular instances of the well-known subset sum problem. While we focus our attacks on two particular instantiations of the TRS, they are generic and are applicable to other schemes with the same choice of domains or a similar structure. We believe this paper can act as an important security remark on the design of future TRS schemes.

In 2011, Eissa, Razak and Ngadi proposed a lightweight authentication and encryption scheme to enhance the performance for mobile ad hoc network in Wireless Network, Vol. 17, No. 4, 2011. The main building block of such scheme is an identity-based encryption scheme. The scheme was proven secure in the random oracle model assuming the computational Diffie–Hellman assumption is hard. In this paper, we show that the proposed scheme is not even secure against chosen plaintext attack, which is the lowest acceptable level of security. In addition, we demonstrate the RSA parameter suggested by Eissa et al. to yield a better network performance is not appropriate under a wrong security assumption that each mobile node is totally trusted. Such short RSA parameter leads to a key recovery attack.

ABSTRACT The Galois/Counter Mode of operations (GCM) is constructed by combining the counter mode encryption and the authentication component (i.e., GTAG) to provide both privacy and authenticity. GTAG can be used as a stand‐alone message authentication code. In this paper, we analyze the security of GTAG and GCM with respect to the forgery and distinguishing attacks. More precisely, We generalize the set of weak key classes proposed by Saarinen in FSE 2012 to include all subsets of nonzero keys. Hence, we remove the condition on the smoothness of 2n − 1, where n denotes the block size, for the existence of weak key classes. By considering powers of suitable field elements and linearized polynomials, we further exploit some specific weak key classes to present a universal forgery attack on GTAG. By invoking the birthday paradox arguments, we show that a chosen message attack can be used to distinguish GTAG from a random function. To relax the assumptions required in the universal forgery attack, we show that we can utilize the uniqueness of the counter mode encryption to launch a known ciphertext attack against GCM itself when the initial vector is restricted to 96 bits. The first three attacks can be applied to other Wegman–Carter polynomial message authentication codes. Copyright © 2013 John Wiley & Sons, Ltd.

Message authentication codes (MACs) are widely used in communication networks for authentication purposes. In EUROCRYPT 2002, Black and Rogaway proposed a parallelizable MAC (PMAC), which is relatively efficient when a parallel environment is possible. This parallelism is achieved via constant multiplications in the underlying finite field. In order to yield a better solution, Rogaway refined PMAC in ASIACRYPT 2004 by using a powering-up construction to generate the constants. This is in contrast to the first design that uses successive words of the gray code to generate the constants. In this paper, we analyze how some unique characteristics of these constants result in weaknesses of the respective PMAC designs against forgery attacks in different ways. Thus, our analysis highlights some pitfalls that designers should be mindful of when designing schemes that exploit such constants.

In 1999, Mohammad Peyravian and Don Coppersmith from IBM proposed a structured symmetric key block cipher called CHAIN that supports variable block size, key size and number of rounds. In this paper, we initiate the study of CHAIN's security. More significantly, we show that CHAIN with various block sizes is insecure against impossible differential attack. To the best of our knowledge, this is the first known attack against CHAIN.

Certificateless encryption refers to public key encryption with implicit certification. Security-mediated certificateless (SMC) encryption takes one-step further, such that every decryption requires a security-mediator (SEM) to partially decrypt the ciphertext. One major benefit is that instant revocation can be done by simply instructing the SEM to reject any further decryption request. Similar to the conventional chosen-ciphertext attack, it is reasonable to assume that an adversary can obtain the partial decryption of many ciphertexts. The authors show that the schemes proposed by Yang-Wang-Wang in AINAW 2007, Lo-Hwang-Li in IET Information Security, 1(3) and Yang-Xiong-Su in Computer Applications, 28(11) are insecure against partial decryption attacks, and hence cannot be classified as SMC encryption according to the original Chow–Boyd–González Nieto's formulation in PKC 2006.