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Data security is very important as it is easy to exchange data today. Cryptographic techniques are needed as data security techniques. Combining two cryptographic algorithms is a solution for a better level of security. The Advanced Encryption Standard (AES) cryptographic algorithm requires low computational power and is the best symmetric algorithm. The LUC algorithm is an asymmetric algorithm that was developed from the RSA algorithm and has advantages in a better level of security and processing speed. In this research, two symmetric and asymmetric cryptographic algorithms will be combined in a hybrid scheme, namely the AES and LUC algorithms to improve data security. the AES algorithm will encrypt and decrypt messages, while the LUC algorithm performs encryption and decryption of the AES key. The results showed that the combination of the two AES and LUC algorithms was successful. However, the computational time needed by the two algorithms to perform the encryption and decryption process increases. The simulation results of the brute force attack performed show that the LUC algorithm can still be attacked. The greater the value of E (the public key of the LUC algorithm), the longer it takes for the brute force attack to be successful. The value of E is also directly proportional to the computational time required by the LUC. So it can be concluded that the AES algorithm is less precise when combined with the LUC algorithm.

The increasing complexity of the cryptographic modeling and security simulation of the Advanced Encryption Standard (AES) necessitate fast modeling and simulation security environment. The SystemC language is used in Electronic System Level (ESL) that allows cryptographic models to achieve high security and modeling simulation speed. Yet, the use of SystemC in the security simulation requires modifications of the original code which increases the modeling complexity. The Aspect-Oriented Programming (AOP) can be used in the cryptographic modeling and security simulations without any code modification. In this paper, a new AES SystemC model using the AOP technique is presented. A functional verification environment is proposed to test the functionality of the AES SystemC AOP model, the impact of AOP on simulation time, and the size of the executable files. The design of the AES model is developed with the weaving of all modules by AspectC++ which is an AOP language. The Simulation results show the efficiency of the proposed AES model and the uses of the AOP technique do not have a significant impact on simulation time or on the size of the executable file.

Cryptographic ransomware encrypts files on a computer system, thereby blocks access to victim’s data, until a ransom is paid. The quick return in revenue together with the practical difficulties in accurately tracking cryptocurrencies used by victims to perform the ransom payment, have made ransomware a preferred tool for cybercriminals. In addition, exploiting zero-day vulnerabilities found in Windows Operating Systems (OSs), the most widely used OS on desktop computers, has enabled ransomware to extend its threat and have detrimental effects at world-wide level. For instance, WannaCry and NotPetya have affected almost all countries, impacted organizations, and the latter alone caused damage which costs more than $10 billion. In this thesis, we conduct a theoretical and experimental study on cryptographic ransomware. In the first part, we explore the anatomy of a ransomware, and in particular, analyze the key management strategies employed by notable families. We verify that for a long-term success, ransomware authors must acquire good random numbers to seed Key Derivation Functions (KDFs). The second part of this thesis analyzes the security of the current anti-ransomware approaches, both in academic literature and real-world systems, with the aim to anticipate how such future generations of ransomware will work, and in order to start planning on how to stop them. We argue that among them, there will be some which will try to defeat current anti-ransomware; thus, we can speculate over their working principles by studying the weak points in the strategies that six of the most advanced anti-ransomware currently implements. We support our speculations with experiments, proving at the same time that those weak points are in fact vulnerabilities and that the future ransomware that we have imagined can be effective. Next, we analyze existing decoy strategies and discuss how they are effective in countering current ransomware by defining a set of metrics to measure their robustness. To demonstrate how ransomware can identify existing deception-based detection strategies, we implement a proof-of-concept decoy-aware ransomware that successfully bypasses decoys by using a decision engine with few rules. We also discuss existing issues in decoy-based strategies and propose practical solutions to mitigate them. Finally, we look for vulnerabilities in antivirus (AV) programs which are the de facto security tool installed at computers against cryptographic ransomware. In our experiments with 29 consumer-level AVs, we discovered two critilcal vulnerabilities. The first one consists in simulating mouse events to control AVs, namely to send them mouse “clicks” to deactivate their protection. We prove that 14 out of 29 AVs can be disabled in this way, and we call this class of attacks Ghost Control. The second one consists in controlling whitelisted applications, such as Notepad, by sending them keyboard events (such as “copy-and-paste”) to perform malicious operations on behalf of the malware. We prove that the anti-ransomware protection feature of AVs can be bypassed if we use Notepad as a “puppet” to rewrite the content of protected files as a ransomware would do. Playing with the words, and recalling the cat-and-mouse game, we call this class of attacks Cut-and-Mouse. In the third part of the thesis, we propose a strategy to mitigate cryptographic ransomware attacks. Based on our insights from the first part of the thesis, we present UShallNotPass which works by controlling access to secure randomness sources, i.e., Cryptographically Secure Pseudo-Random Number Generator (CSPRNG) Appliction Programming Interfaces (APIs). We tested UShallNotPass against 524 real-world ransomware samples, and observe that UShallNotPass stops 94% of them, including WannaCry, Locky, CryptoLocker and CryptoWall. Remarkably, it also nullifies NotPetya, the offspring of the family which so far has eluded all defenses. Next, we present NoCry, which shares the same defense strategy but implements an improved architecture. We show that NoCry is more secure (with components that are not vulnerable to known attacks), more effective (with less false negatives in the class of ransomware addressed) and more efficient (with minimal false positive rate and negligible overhead). To confirm that the new architecture works as expected, we tested NoCry against a new set of 747 ransomware samples, of which, NoCry could stop 97.1%, bringing its security and technological readiness to a higher level. Finally, in the fourth part, we present the potential future of the cryptographic ransomware. We identify new possible ransomware targets inspired by the cybersecurity incidents occurred in real-world scenarios. In this respect, we described possible threats that ransomware may pose by targeting critical domains, such as the Internet of Things and the Socio-Technical systems, which will worrisomely amplify the effectiveness of ransomware attacks. Next, we looked into whether ransomware authors re-use the work of others, available at public platforms and repositories, and produce insecure code (which might enable to build decryptors). By methodically reverse-engineering malware executables, we have found that, out of 21 ransomware samples, 9 contain copy-paste code from public resources. From this fact, we recall critical cases of code disclosure in the recent history of ransomware and, reflect on the dual-use nature of this research by arguing that ransomware are components in cyber-weapons. We conclude by discussing the benefits and limits of using cyber-intelligence and counter-intelligence strategies that could be used against this threat.

International audience; In the last decade, Blockchain has experienced a booming success. It is on everybody's lips, in particular in the banking and finance world where it finds its source. Many authors have explored the potential influence of Blockchain on the market. Blockchain brings digital technology into real time computing systems management. It has the ability to transform all aspects of the digital economy, including conducting business, shopping, enhancing education, delivering healthcare, and learning, entertainment, and staying connected with a social world. Blockchain was not in fact created for its own intents and purposes originally, it was only an aspect of Bitcoin protocol, ensuring the secure transfer of the cryptocurrency. In this paper, we are providing an introduction to Blockchain technology in a simplified style. It also discusses about how Blockchain technology can be used in the market to benefit the customers and the company to a great extent. Lately, Blockchain digital technology has evolved further to aid in conducting financial transactions. Online payments have gained large traction and card based payment methods, credit and debit cards have become dominant. Blockchain supports all these transform by creating increased speed of transaction processing and greater efficiency in real time processing. Blockchain provides a robust environment for secure data sharing in real-time. Blockchain is a type of distributed ledger system providing enhanced security in the real time digital economic process.

Blockchain tehnologija jedna je od najatraktivnijih tehnologija u računalnom svijetu unazad deset godina. Pozornost je privukla 2008. godine kada je netko pod pseudonimom Satoshi Nakamoto iskoristio sve prednosti blockchain tehnologija za kreiranje digitalnog novca Bitcoin. Temeljne karakteristike blockchain tehnologije su nepromjenjivost i sigurnost. Jednom zapisani podaci ne mogu biti promijenjeni niti brisani, dok sigurnost pružaju kriptografski algoritmi. Ova tehnologija može se koristiti u raznim područjima kao što su financijski sektor, medicina, prehrambena industrija, trgovina i dr. U ovom radu detaljno je prikazano kreiranje programskog rješenja koristeći blockchain tehnologiju. Programsko rješenje omogućuje zapisivanje temperature izmjerene u nekom od četiri entiteta u lancu dostave hrane na blockchain. Takvim rješenjem rješava se problem povjerenja između entiteta, jer jednom zapisani podaci ne mogu biti izmijenjeni. Blockchain technology is one of the most advanced technologies in the computer world back in ten years. It attracted attention in 2008 when someone under the pseudonym Satoshi Nakamoto exploited all the advantages of blockchain technology for creating digital money Bitcoin. The fundamental features of blockchain technology are immutability and security. Once written data can not be changed or deleted, while security provides cryptographic algorithms. This technology can be used in a variety of areas, such as the financial sector, medicine, food industry, commerce, etc. In this paper, we have detailed the creation of a software solution using blockchain technology. The program solution allows you to record the temperature measured in any of the four entities in the food chain at the blockchain. Such a solution resolves the problem of trust between the entities, because once recorded data can not be altered.

2017 - 2018, The following doctoral thesis comprises two distinct sections, both describing a specific applied research concerning the macro-theme of computer security. The first section describes a proposal for the improvement and optimization of the storage space required for the management of cryptographic keys within a Hardware Security Module (HSM), whereas the second section outlines the design of an Outdoor Position Certification Authority (OPCA), a distributed client-server architecture aimed for the validation and certification of the positioning of a mobile device. A Hardware Security Module is a special device designed for cryptographic operations and cryptographic keys management. The latter keys are stored into the HSM and never exposed outside the device. All the operations carried out through the keys are performed inside the HSM so the operations result is indeed the only external outcome produced by the HSM. In order for the HSM to store all the keys that have to be managed, plenty of storage space is required. The biggest data centres, handling millions of cryptographic keys, need to host a large number of HSMs. The related costs are proportional to the number of HSMs used. These costs include: hardware, energy consumption, network hosting, network speed, management, etc. In this thesis, there can be found two methods to save the space useful for the storage of the keys in a HSM, so to reduce the number of HSMs needed and all related costs. While reducing costs on storage, expenses related to computation time will increase. The outlined Outdoor Position Certification Authority represents the project and design of a certification authority whose purpose is to certify the positioning of a mobile device equipped with a GNSS (Global Navigation Satellite System) receiver. In general, a GNSS receiver is capable of acquiring radio signals (lowlevel data) and navigation messages (high-level data) in the outdoor environments coming from different constellations of global/regional satellite navigation systems and satellite-based augmentation system (SBAS). To date, these data are not reliable from a security point of view, because they can be easily forged by malicious attackers through specialized spoofing techniques. An OPCA defines a client/server architecture through which a user can certify his position by sending to one or more remote servers the geo-localization information required for its verification. Once the truthfulness and reliability of the data received have been verified, the OPCA will issue and then send to the client a digitally signed document having legal force and certifying the position of the user in a given moment. The use of this service will concern different and multiple scenarios and the devices requiring it will extensively grow in number thanks to the spread of the Internet of Things (IoT). Here are some possible scenarios: remote digital signing of a document for users located in a specific place; certification of the geographical position of a user in a given moment; certification of geographical position related to the delivery of valuable goods; certification of geographical position in case of critical events, such as rescue operations, police actions, etc. The first section of this thesis has been carried out based on two scientific publications. The first one, entitled “Reducing Costs in HSM-Based Data Centres”, is a conference publication presented during the “International Conference on Green, Pervasive, and Cloud Computing 2017 (GPC 2017) at Cetara (SA)”. This paper offers a first experimental evaluation of what will be found in the next pages and referred to as “Enhanced HSM (EHSM)”. The second paper is a journal version, published in the “Journal of High Speed Networks (JHSN) - IOS Press”. In this publication, an alternative approach has been illustrated in relation to the issue of space storage in the key management of a HSM. The second section of the thesis is based on an International Patent registered at the European Patent Organization (EPO), its official number being EP 18724344.9, and on a related paper, being completed, entitled “Design of an Outdoor Position Certification Authority”. [edited by author]

In order to detect malicious file system activity, some commercial and academic anti-ransomware solutions implement deception-based techniques, specifically by placing decoy files among user files. While this approach raises the bar against current ransomware, as any access to a decoy file is a sign of malicious activity, the robustness of decoy strategies has not been formally analyzed and fully tested. In this paper, we analyze existing decoy strategies and discuss how they are effective in countering current ransomware by defining a set of metrics to measure their robustness. To demonstrate how ransomware can identify existing deception-based detection strategies, we have implemented a proof-ofconcept anti-decoy ransomware that successfully bypasses decoys by using a decision engine with few rules. Finally, we discuss existing issues in decoy-based strategies and propose practical solutions to mitigate them.

International audience; Nowadays, chaos-based cryptographicprimitives are used as an alternative to classicalcryptographic primitives for data security. Indeed, thisis because the fact that there is intrinsic randomnessin chaotic signals and ease of designing robust chaosbasedcryptographic primitives. A common andimportant element in chaos-based cryptography isthe Pseudo-Chaotic Number Generator (PCNG).A variety of PCNG with software implementationhas been published in the literature. However, dueto the rapid growth of Internet of Things (IoT),it is necessary to have such primitive in hardwareimplementation such as an FPGA. In this paper weaddress the hardware implementation on SAKURA-GFPGA-board using VHDL, of one of our PCNGs thatwas designed, implemented in C code and analyzed.We realized also the implementation in Matlab,for approving our hardware implementation. Theperformance of the hardware implementation in termsof statistical tests, throughput and logic resources iscompared with some other PCNGs.

Secure and reliable communication have always been critical part of todays infrastructure. Various asymmetric encryption schemes, such as RSA, have been used to achieve this goal. However, with advancements in quantum computing, current encryption schemes are becoming more vulnerable since they are weak to certain quantum attacks, such as Shor’s Algorithm. Therefore demand for post-quantum cryptography (PQC), which is not vulnerable to quantum attacks, is apparent. This work’s goal is to evaluate and compare PQC algorithms.

At the heart of the creation of modern cryptographic systems is the use of cryptographic primitives. This has as its main goal of providing high security created cryptographic primitives and cryptosystem. For the development of cryptographic primitives used various mathematical transformations. To evaluate the security of cryptographic primitives are used very different approaches. The paper proposes a universal approach to the assessment of security of any cryptographic primitives. Cryptographic primitive - algorithms of reversible transformation of the block of the data of the fixed size with use of a set of key parameters of the fixed size is offered. It shown that substitution is a base cryptographic primitive through which it is possible to express all the others. At the heart of the offered approach lies the theorem of C. Shannon that defines perfect secrecy for secret-key systems and shows that they exist. For perfect security receive it is necessary, that the size of a key was not less than size of the converted data and the key was in regular intervals distributed. Matrix representation of similar system is a Latin square - rectangular table, in each line and each column all elements are various. For maximum security of cryptographic primitives defined optimal parameters of the substitutions table. For a number of cryptographic primitives obtained analytical and prognostic assessment of their security based on proximity to the Latin square.

12-19 Описаны алгоритмы формирования и проверки электронной подписи по ГОСТ Р 34.10- 2012 и по алгоритму RSA в Microsoft Visual Studio 2012. The algorithms of generation and verification electronic signature in accordance with GOST R 34.10- 2012 and the RSA algorithm in the Microsoft Visual Studio 2012.

12-19 Описаны алгоритмы формирования и проверки электронной подписи по ГОСТ Р 34.10- 2012 и по алгоритму RSA в Microsoft Visual Studio 2012. The algorithms of generation and verification electronic signature in accordance with GOST R 34.10- 2012 and the RSA algorithm in the Microsoft Visual Studio 2012.

This article presents both the description and results of the Threefish cryptographic algorithm hardware implementation for encryption process. The implementation of the algorithm was performed by using the iterative round architecture on the FPGA (Field Programmable Gate Array) Virtex-5 present in the development system XUPV5-LX110T. Place and route results show that the design Threefish-256 iterative round has a throughput of 551Mbps. En este artículo se presenta la descripción y los resultados de la implementación en hardware del algoritmo criptográfico Threefish en su proceso de cifrado. La implementación se realizó usando la arquitectura de ronda iterativa sobre la Field Programmable Gate Array (FPGA) Virtex-5 presente en el sistema de desarrollo XUPV5-LX110T. Los resultados posteriores al place and route muestran que el diseño Threefish-256 de ronda iterativa tiene un throughput de 551Mbps.

En este artículo se presenta la descripción y los resultados de la implementación en hardware del algoritmo criptográfico Threefish en su proceso de cifrado. La implementación se realizó usando la arquitectura de ronda iterativa sobre la Field Programmable Gate Array (FPGA) Virtex-5 presente en el sistema de desarrollo XUPV5-LX110T. Los resultados posteriores al place and route muestran que el diseño Threefish-256 de ronda iterativa tiene un throughput de 551Mbps. This article presents both the description and results of the Threefish cryptographic algorithm hardware implementation for encryption process. The implementation of the algorithm was performed by using the iterative round architecture on the FPGA (Field Programmable Gate Array) Virtex-5 present in the development system XUPV5-LX110T. Place and route results show that the design Threefish-256 iterative round has a throughput of 551Mbps.

Increased demand for data security is an undeniable fact. Towards achieving higher security, cryptographic algorithms play an important role in the protection of data from unapproved usage. In this paper, we present a crypto processor using Advanced Encryption Standard (AES). The AES is integrated with a 32-bit general purpose 5-stage pipelined MIPS processor. The integrated AES module is a fully pipelined module which follows inner round and outer round pipeline design. The results show that the presented pipeline version of the AES algorithm along with MIPS processor outperforms traditional methods. At the operating frequency of 553 MHz, the proposed design can achieve the throughput of 58 Gbps, the latency of 240 ns, and the minimum power consumption of 76 mw.

Advancements in technology have created the possibility of greater assurance of proper travel document ownership, but some concerns regarding security and effectiveness remain unaddressed. Electronic passports have known a wide and fast deployment all around the world since the International Civil Aviation Organization the world has adopted standards whereby passports can store biometric identifiers. The use of biometrics for identification has the potential to make the lives easier, and the world people live in a safer place. The purpose of biometric passports is to prevent the illegal entry of traveler into a specific country and limit the use of counterfeit documents by more accurate identification of an individual. This paper analyses the face, fingerprint, palmprint and iris biometric e-passport design. This papers focus on privacy and personal security of bearers of e-passports, the actual security benefit countries obtained by the introduction of e-passports using face, fingerprint, palmprint and iris recognition systems. Researcher analyzed its main cryptographic features; the face fingerprint, palmprint and iris biometrics currently used with e-passports and considered the surrounding procedures. Researcher focused on vulnerabilities since anyone willing to bypass the system would choose the same approach. On the contrary, solely relying on them may pose a risk that did not exist with previous passports and border controls. The paper also provides a security analysis of the e-passport using face fingerprint, palmprint and iris biometric that are intended to provide improved security in protecting biometric information of the e-passport bearer.

In the world of Internet nothing is really safe. There's always a gap in any application made. Likewise in email delivery. To minimize attacks on the data transmission is usually applied cryptography. One fairly popular cryptographic algorithms are RSA algorithm. In this study will discuss the implementation of a cryptographic algorithm RSA encryption and decryption process email. To test created a java-based email client program with message encryption and decryption features messages. This application uses the Java programming language and Netbeans 7.4 as editor. Mail servers used is Google Mail. The initial step of this study was to download email from the Google server and encrypt the message. The second step is decrypt the message to verify whether the message is still the same as the original message before it is encrypted . Results from this study is the application that can encrypt and decrypt messages using RSA cryptographic algorithm. With this application is expected to mail delivery is much safer. Because encrypted email will generate a random decimal number of unknown value .

Construcción de un cifrador basado en una permutación pseudo-aleatoria (Castañeda Marín, Hernando y Rodríguez Graterol, Wladimir) Abstract The purpose of this paper is the analysis and development of as practical implementation of a cipher based on the schema proposed by Even and Mansour[1]. The schema corresponds to a block cipher based in the use of a permutation in the encryption operation and in the corresponding inverse function for the decryption process. The key K that consist in two sub keys K1 and K2, which are produce by means of a pseudorandom numbers generator with unpredictable inputs and pseudorandom output sequences. To measure the reliability of the permutation of the resulting sequence of the previous XOR operation, hypothesis test were done using the statistic X2 for different combinations of the { 0,1 } patterns referenced in those sequences. In order to reach this purpose the Yarrow-160, a visual C++ software from Counterpane System, computational tool was used; extended with the necessary encryption and decryption routines for the proposed cryptosystem based on the Even and Mansour schema. Also a routine was added, that allows doing statistical test by determining the computed values of X2 for the different combinatorial patterns of the sequences. This work is an academicals practice to test the strengths and debilities of the Counterpane System software and allows to extend it by means of the construction of a cipher based on a simple permutation that, as practical implementation allows the test of its computational complexity and security. The realization of a cryptanalysis and the realization of different cryptographic attacks will made possible future works in the field of cryptographic and computational security. Ponencia dictada en: XXXI Conferencia Latinoamericana de Informática - CLEI2005. Cali-Colombia, del 10 al 14 de octubre de 2005. hcastaneda@ula.ve, hcastaneda@unipamplona.edu.co wladimir@ula.ve Nivel monográfico

Business and organizations use computer network in a greater extension than ever before, especially for business-critical use. That increase the demand of security for all systems, both against internal and external threats. The demand on the authentication method used today increases. Today they normally uses password or some kind of smart card. I will performa literature study that will investigate the possibility to increase the security in authentication of users without the use of extra hardware. The method uses a server that stores all cryptographic keys for the user centrally to achieve stronger security. This report is based on a previous report which tested to implement this solution, in this report I will question the security of this system. I will then give an architecture proposal where this method is used to authenticate and allow cryptographic recourses for the user. The conclusions you can get from this report is that the possibilities with comparable ease increase the security without investing in new hardware. But the solution will not be comparable by a ``smart card solution''in security levels. That means that the method described in this thesis is suitable for organizations that either do not need that strong security as smart card give or want a good solution without being forced to use some external hardware.

Business and organizations use computer network in a greater extension than ever before, especially for business-critical use. That increase the demand of security for all systems, both against internal and external threats. The demand on the authentication method used today increases. Today they normally uses password or some kind of smart card. I will performa literature study that will investigate the possibility to increase the security in authentication of users without the use of extra hardware. The method uses a server that stores all cryptographic keys for the user centrally to achieve stronger security. This report is based on a previous report which tested to implement this solution, in this report I will question the security of this system. I will then give an architecture proposal where this method is used to authenticate and allow cryptographic recourses for the user. The conclusions you can get from this report is that the possibilities with comparable ease increase the security without investing in new hardware. But the solution will not be comparable by a ``smart card solution''in security levels. That means that the method described in this thesis is suitable for organizations that either do not need that strong security as smart card give or want a good solution without being forced to use some external hardware.

RFID is an identication technology that has a wide range of applications. One of the main areas of interest is the Supply Chain Management (SCM), traceability management, multimodality shopping, etc. In suppy chains readers are placed into manufacturing facilities, the supplier attaches RFID tags to all outgoing products and some data is stored on each tag , attached to the products. At each stage, every player in the supply chain will be able to track relevant information on the product. The information can be used to ensure quality, on time delivery, fast re-stocks, ad hence greater overall e ciency. NSCCA (Nested Supply Chain Cryprographic System) is an algorithm derived from the Nested Cryptographic Algorithm, that aims to ensure authenticity, privacy and protection along one suppy chain, and is based on public cryptog- raphy. The scope of this project is to develop a programming class library and an appli- cation that implement the NSCCA algorithm, as well as testing its performance, as well as an interface that permit to communicate through an RFID reader in order to save and load the result of the algorithm in RFID tags. structure of this report is as follows: In Chapter 2, some important concepts involved in the project are explained, as well as the NSSCA algorithm, public key cryptography and RFID technology. Then, in Chapter 3 the development framework (programming language, ID) is explained, and the program structure is de ned. Continuing, the Chapter 4some tests on the platform are performed, and the main results are discussed. After that, in Chapter 5 there is a little user manual for the application developed to test the libraries. Finally, in Chapter 6 the conclussions on the project realization are explained.