scholarly journals Reversible and Plausibly Deniable Covert Channels in One-Time Passwords Based on Hash Chains

2021 ◽  
Vol 11 (2) ◽  
pp. 731
Author(s):  
Jörg Keller ◽  
Steffen Wendzel
Keyword(s):  
Hash Function ◽  
Statistical Tests ◽  
Ip Networks ◽  
Covert Channel ◽  
Covert Channels ◽  
Cryptographic Primitives ◽  
Driven Systems ◽  
Time Performance ◽  
Covert Communications ◽  
Binary Strings

Covert channels enable stealthy communications over innocent appearing carriers. They are increasingly applied in the network context. However, little work is available that exploits cryptographic primitives in the networking context to establish such covert communications. We present a covert channel between two devices where one device authenticates itself with Lamport’s one-time passwords based on a cryptographic hash function. Our channel enables plausible deniability jointly with reversibility and is applicable in different contexts, such as traditional TCP/IP networks, CPS/IoT communication, blockchain-driven systems and local inter-process communications that apply hash chains. We also present countermeasures to detect the presence of such a covert channel, which are non-trivial because hash values are random-looking binary strings, so that deviations are not likely to be detected. We report on experimental results with MD5 and SHA-3 hash functions for two covert channel variants running in a localhost setup. In particular, we evaluate the channels’ time performance, conduct statistical tests using the NIST suite and run a test for matching hash values between legitimate and covert environments to determine our channels’ stealthiness.

scholarly journals On the correlation and sensitivity of so far statistical randomness tests based on runs

2022 ◽  
Vol 2 (14) ◽  
pp. 55-65
Author(s):  
Hoang Dinh Linh ◽  
Do Dai Chi ◽  
Nguyen Tuan Anh ◽  
Le Thao Uyen
Keyword(s):  
Statistical Tests ◽  
Random Sequence ◽  
Random Numbers ◽  
Expected Number ◽  
Cryptographic Primitives ◽  
Pearson Coefficient ◽  
Strong Linear Correlation ◽  
Cryptographic Algorithms ◽  
Coefficient Method ◽  
Randomness Tests

Abstract—Random numbers play a very important role in cryptography. More precisely, almost cryptographic primitives are ensured their security based on random values such as random key, nonces, salts... Therefore, the assessment of randomness according to statistical tests is really essential for measuring the security of cryptographic algorithms. In this paper, we focus on so far randomness tests based on runs in the literature. First, we have proved in detail that the expected number of gaps (or blocks) of length  in a random sequence of length  is . Secondly, we have evaluated correlation of some tests based on runs so far using Pearson coefficient method [5, 6] and Fail-Fail ratio one [7, 8]. Surprisingly, the Pearson coefficient method do not show any strong linear correlation of these runs-based tests but the Fail-Fail ratio do. Then, we have considered the sensitivity of these runs tests with some basic transformations. Finally, we have proposed some new runs tests based on the sensitivity results and applied evaluations to some random sources. Tóm tắt—Số ngẫu nhiên đóng một vai trò quan trọng trong mật mã. Cụ thể, độ an toàn của hầu hết các nguyên thủy mật mã đều được đảm bảo dựa trên các giá trị ngẫu nhiên như khóa, nonce, salt… Do đó, việc đánh giá tính ngẫu nhiên dựa trên các kiểm tra thống kê là thực sự cần thiết để đo độ an toàn cho các thuật toán mật mã. Trong bài báo này, chúng tôi tập trung vào các kiểm tra ngẫu nhiên dựa vào run trong các tài liệu. Đầu tiên, chúng tôi chứng minh chi tiết rằng kỳ vọng số các gap (khối) độ dài  trong một chuỗi ngẫu nhiên độ dài  là . Sau đó, chúng tôi đánh giá mối tương quan của một số kiểm tra dựa vào run bằng phương pháp hệ số Pearson [5, 6] và tỷ số Fail-Fail  [7, 8]. Đáng ngạc nhiên là phương pháp hệ số Pearson không cho thấy bất kỳ mối tương quan tuyến tính mạnh nào của các kiểm tra dựa vào run, trong khi đó tỷ số Fail-Fail lại chỉ ra. Tiếp theo, chúng tôi xem xét độ nhạy của các kiểm tra run này với một số phép biến đổi cơ bản. Cuối cùng, chúng tôi đề xuất một số kiểm tra run mới dựa trên các kết quả độ nhạy và đánh giá áp dụng chúng cho một số nguồn ngẫu nhiên.

scholarly journals Addressing Covert Channel Attacks in RFID-Enabled Supply Chains

2013 ◽  
pp. 176-190
Author(s):  
Kirti Chawla ◽  
Gabriel Robins
Keyword(s):  
Supply Chain ◽  
Supply Chains ◽  
Network Flow ◽  
Economic Effects ◽  
Future Research ◽  
Covert Channel ◽  
Covert Channels ◽  
Node Selection ◽  
Future Research Directions ◽  
Key Nodes

RFID technology can help competitive organizations optimize their supply chains. However, it may also enable adversaries to exploit covert channels to surreptitiously spy on their competitors. We explain how tracking tags and compromising readers can create covert channels in supply chains and cause detrimental economic effects. To mitigate such attacks, the authors propose a framework that enables an organization to monitor its supply chain. The supply chain is modeled as a network flow graph, where tag flow is verified at selected key nodes, and covert channels are actively sought. While optimal taint checkpoint node selection is algorithmically intractable, the authors propose node selection and flow verification heuristics with various tradeoffs. The chapter discusses economically viable countermeasures against supply chain-based covert channels, and suggests future research directions.

scholarly journals Ordinal synchronization mark sequence and its steganography for a multi-link network covert channel

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252813
Author(s):  
Songyin Fu ◽  
Rangding Wang ◽  
Li Dong ◽  
Diqun Yan
Keyword(s):  
Hash Function ◽  
High Capacity ◽  
Superior Performance ◽  
Covert Channel ◽  
Correlation Test ◽  
Switching Patterns ◽  
Finite Set ◽  
Set Up ◽  
Network Covert Channel ◽  
Real Traffic

A multi-link network covert channel (MLCC) such as Cloak exhibits a high capacity and robustness and can achieve lossless modulation of the protocol data units. However, the mechanism of Cloak involving an arrangement of packets over the links (APL) is limited by its passive synchronization schemes, which results in intermittent obstructions in transmitting APL packets and anomalous link switching patterns. In this work, we propose a novel ordinal synchronization mark sequence (OSMS) for a Cloak framework based MLCC to ensure that the marked APL packets are orderly distinguishable. Specifically, a unidirectional function is used to generate the OSMS randomly before realizing covert modulation. Subsequently, we formulate the generation relation of the marks according to their order and embed each mark into the APL packets by using a one-way hash function such that the mark cannot be cracked during the transmission of the APL packet. Finally, we set up a retrieval function of the finite set at the covert receiver to extract the marks and determine their orders, and the APL packets are reorganized to realize covert demodulation. The results of experiments performed on real traffic indicated that the MLCC embedded with OSMS could avoid the passive synchronization schemes and exhibited superior performance in terms of reliability, throughput, and undetectability compared with the renowned Cloak method, especially under a malicious network interference scenario. Furthermore, our approach could effectively resist the inter-link correlation test, which are highly effective in testing the Cloak framework.

scholarly journals A New Sensors-Based Covert Channel on Android

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Ahmed Al-Haiqi ◽  
Mahamod Ismail ◽  
Rosdiadee Nordin
Keyword(s):  
Covert Channel ◽  
Security Model ◽  
Covert Channels ◽  
Computing Systems ◽  
Collusion Attacks ◽  
Acceleration Data ◽  
Universal Solution ◽  
Android Platform ◽  
New Sensors ◽  
Explicit Communication

Covert channels are not new in computing systems, and have been studied since their first definition four decades ago. New platforms invoke thorough investigations to assess their security. Now is the time for Android platform to analyze its security model, in particular the two key principles: process-isolation and the permissions system. Aside from all sorts of malware, one threat proved intractable by current protection solutions, that is, collusion attacks involving two applications communicating over covert channels. Still no universal solution can countermeasure this sort of attack unless the covert channels are known. This paper is an attempt to reveal a new covert channel, not only being specific to smartphones, but also exploiting an unusual resource as a vehicle to carry covert information: sensors data. Accelerometers generate signals that reflect user motions, and malware applications can apparently only read their data. However, if the vibration motor on the device is used properly, programmatically produced vibration patterns can encode stolen data and hence an application can cause discernible effects on acceleration data to be received and decoded by another application. Our evaluations confirmed a real threat where strings of tens of characters could be transmitted errorless if the throughput is reduced to around 2.5–5 bps. The proposed covert channel is very stealthy as no unusual permissions are required and there is no explicit communication between the colluding applications.

scholarly journals A Survey of Key Technologies for Constructing Network Covert Channel

2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Jing Tian ◽  
Gang Xiong ◽  
Zhen Li ◽  
Gaopeng Gou
Keyword(s):  
Communication Technology ◽  
Network Architecture ◽  
The Internet ◽  
Covert Channel ◽  
Free Access ◽  
Transmission Network ◽  
Information Channel ◽  
Covert Channels ◽  
Key Technologies ◽  
Network Covert Channel

In order to protect user privacy or guarantee free access to the Internet, the network covert channel has become a hot research topic. It refers to an information channel in which the messages are covertly transmitted under the network environment. In recent years, many new construction schemes of network covert channels are proposed. But at the same time, network covert channel has also received the attention of censors, leading to many attacks. The network covert channel refers to an information channel in which the messages are covertly transmitted under the network environment. Many users exploit the network covert channel to protect privacy or guarantee free access to the Internet. Previous construction schemes of the network covert channel are based on information steganography, which can be divided into CTCs and CSCs. In recent years, there are some covert channels constructed by changing the transmission network architecture. On the other side, some research work promises that the characteristics of emerging network may better fit the construction of the network covert channel. In addition, the covert channel can also be constructed by changing the transmission network architecture. The proxy and anonymity communication technology implement this construction scheme. In this paper, we divide the key technologies for constructing network covert channels into two aspects: communication content level (based on information steganography) and transmission network level (based on proxy and anonymity communication technology). We give an comprehensively summary about covert channels at each level. We also introduce work for the three new types of network covert channels (covert channels based on streaming media, covert channels based on blockchain, and covert channels based on IPv6). In addition, we present the attacks against the network covert channel, including elimination, limitation, and detection. Finally, the challenge and future research trend in this field are discussed.

Research on Construction Methods for Network Covert Channels Based on HTTP

2012 ◽  
Vol 220-223 ◽  
pp. 2528-2533
Author(s):  
Ran Zhang ◽  
Yong Gan ◽  
Yi Feng Yin
Keyword(s):  
Network Traffic ◽  
Covert Channel ◽  
Construction Technology ◽  
Traffic Data ◽  
Covert Channels ◽  
Secret Data ◽  
Construction Methods ◽  
Working Principle ◽  
Network Covert Channel

Network covert channel is a steganography technology that uses network traffic data as a carrier to transfer the secret data. This paper analyzes the working principle of network covert channels, and summarizes the commonly used construction technology of network covert channels. Then it analyzes the characteristics of the HTTP header lines and gives some methods of constructing network covert channels with these characteristics. Network covert channels based on the HTTP header lines are simple, flexible, and difficult to be detected and shielded.

scholarly journals A Wireless Covert Channel Based on Dirty Constellation with Phase Drift

Electronics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 647
Author(s):  
Krystian Grzesiak ◽  
Zbigniew Piotrowski ◽  
Jan M. Kelner
Keyword(s):  
Software Defined Radio ◽  
Modulation Method ◽  
Practical Implementation ◽  
Covert Channel ◽  
Audio Signals ◽  
Covert Channels ◽  
Simulation Research ◽  
Phase Drift ◽  
Modulation Type ◽  
Shift Keying

Modern telecommunications systems require the use of various transmission techniques, which are either open or hidden. The open transmission system uses various security techniques against its unauthorized reception, and cryptographic solutions ensure the highest security. In the case of hidden transmissions, steganographic techniques are used, which are based on the so-called covert channels. In this case, the transparency and stealth of the transmission ensure its security against being picked up by an unauthorized user. These covert channels can be implemented in multimedia content, network protocols, or physical layer transmissions. This paper focuses on wireless covert channels. We present a novel method of steganographic transmission which is based on phase drift in phase-shift keying or quadrature amplitude modulation (QAM) and is included in the so-called dirty constellation techniques. The proposed approach is based on the drift correction modulation method, which was previously used in the watermarking of audio-signals. The developed solution is characterized by a variable bit rate, which can be adapted to the used modulation type and transmission conditions occurring in radio channels. In the paper, we present the method of generating and receiving hidden information, simulation research, and practical implementation of the proposed solution using the software-defined radio platform for selected QAM.

Survey of Transient Execution Attacks and Their Mitigations

2021 ◽  
Vol 54 (3) ◽  
pp. 1-36
Author(s):  
Wenjie Xiong ◽  
Jakub Szefer
Keyword(s):  
Information Leakage ◽  
Speculative Execution ◽  
Covert Channel ◽  
Covert Channels ◽  
Critical Data ◽  
Different Types ◽  
Temporal And Spatial ◽  
Main Components ◽  
First Disclosure

Transient execution attacks, also known as speculative execution attacks, have drawn much interest in the last few years as they can cause critical data leakage. Since the first disclosure of Spectre and Meltdown attacks in January 2018, a number of new transient execution attack types have been demonstrated targeting different processors. A transient execution attack consists of two main components: transient execution itself and a covert channel that is used to actually exfiltrate the information.Transient execution is a result of the fundamental features of modern processors that are designed to boost performance and efficiency, while covert channels are unintended information leakage channels that result from temporal and spatial sharing of the micro-architectural components. Given the severity of the transient execution attacks, they have motivated computer architects in both industry and academia to rethink the design of the processors and to propose hardware defenses. To help understand the transient execution attacks, this survey summarizes the phases of the attacks and the security boundaries across which the information is leaked in different attacks.This survey further analyzes the causes of transient execution as well as the different types of covert channels and presents a taxonomy of the attacks based on the causes and types. This survey in addition presents metrics for comparing different aspects of the transient execution attacks and uses them to evaluate the feasibility of the different attacks. This survey especially considers both existing attacks and potential new attacks suggested by our analysis. This survey finishes by discussing different mitigations that have so far been proposed at the micro-architecture level and discusses their benefits and limitations.

scholarly journals A New Statistical Test for PRNG Based on the Attendance’s Law

2021 ◽  
pp. 37-46
Author(s):  
Babacar Alasane Ndaw ◽  
Ousmane Ndiaye ◽  
Mamadou Sanghar´e ◽  
Cheikh Thi´ecoumba Gueye
Keyword(s):  
Random Number ◽  
Statistical Tests ◽  
Random Number Generator ◽  
Deterministic Algorithm ◽  
Statistical Test ◽  
The Other ◽  
Cryptographic Primitives ◽  
Random Number Generators ◽  
Other Hand ◽  
The One

One family of the cryptographic primitives is random Number Generators (RNG) which have several applications in cryptography such that password generation, nonce generation, Initialisation vector for Stream Cipher, keystream. Recently they are also used to randomise encryption and signature schemes. A pseudo-random number generator (PRNG) or a pseudo-random bit generator (PRBG) is a deterministic algorithm that produces numbers whose distribution is on the one hand indistinguishable from uniform ie. that the probabilities of appearance of the different symbols are equal and that these appearances are all independent. On the other hand, the next output of a PRNG must be unpredictable from all its previous outputs. Indeed, A set of statistical tests for randomness has been proposed in the literature and by NIST to evaluate the security of random(pseudo) bit or block. Unfortunately there are non-random binary streams that pass these standardized tests. In this pap er, as outcome, we intro duce on the one hand a new statistical test in a static contextcalled attendance’s law and on the other hand a distinguisher based on this new attendance’s law.    

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