Security Goals Research Articles

Do rotations and intercrops matter? Opportunities for intensification and diversification of maize-based cropping systems in Zambia

ContextRealizing the double-edged goals of food security and crop diversification require knowledge of crop yield response to different agricultural practices and the extent to which such response is context dependent. This is particularly important in Southern Africa where cropping systems are dominated by maize and smallholders use few external inputs. ObjectiveThe objectives of this study were (1) to evaluate the performance of cropping systems with different levels of legume diversification and intensification on maize productivity across the main agroecological zones and farming systems of Zambia, and (2) to establish the minimum land required to reach maize self-sufficiency at household level with the different cropping systems tested. MethodsSix maize-based cropping systems, comprising maize monocropping, maize-legume rotations and intercrops under ‘conventional’ tillage and conservation agriculture, were evaluated across 40 farms in contrasting agro-ecological zones and farming systems of Zambia. A household survey was conducted in the same communities hosting the on-farm trials to quantify the share of households with enough maize cultivated area to benefit from the tested cropping systems. ResultsMaize yield measured in the on-farm trials ranged, on average, between 3.6 and 5.4 t ha−1, which was greater than mean maize yields reported by farmers not hosting on-farm trials during the same growing seasons and in the same sites. Our results showed a clear positive effect of legume rotation on maize yield in Eastern province only, where cropping systems including groundnut as rotation crop yielded between 1.0 and 2.0 t ha−1 more maize than other cropping systems. Pigeon pea intercrops and Gliricidia hedgerows, crop residue management, and tillage practice had no significant effect on maize yield in any of the provinces. Finally, nearly 35, 50, and 70% of surveyed farms in Northern, Eastern, and Southern province would have enough land to achieve the same level of maize production obtained on their farm with the yields, and associated area requirements, of the maize-legume rotations tested in the on-farm trials. ConclusionLegume rotations can increase maize productivity on land abundant farms in high potential maize production areas of Southern Africa, whereas legume intercrops have benefits at cropping systems level and should be targeted to land constrained farms. SignificanceThe study contributes to better understand the niche for diversified maize-based cropping systems with legume rotations and intercrops in Southern Africa, along with their impacts on maize productivity at the field level and their land requirements at the farm level.

Literature review of food insecurity in the Sahel from an interdisciplinary perspective

ABSTRACT This paper fills a gap in the literature by consolidating existing literature on food insecurity in the Sahel region. We explore the literature by considering the four primary characteristics of food security, namely; food accessibility, availability, utilisation, and stability. We further examine three crucial factors impacting food insecurity – climate change, conflict, and COVID-19 - as identified by the UN. This paper aims to provide researchers with an interdisciplinary perspective to build decision analysis systems through multidimensional exploration. We discuss the contributions as well as the limitations of this research. In general, our literature review also contributes to global as well as region-specific food security goals.

International development policies in Central and Eastern Europe since EU accession: increasing divergence?

ABSTRACT The contribution discusses how the international development policies of four Central and Eastern European (CEE) countries (the Czech Republic, Hungary, Poland and Slovakia) evolved following their accession to the EU. The four states started these policies in the run-up to accession, driven by pressure from the EU. The policies put in place were underfunded and received little political attention, resulting in functionally similar approaches. In the past 10 years however, these policies began to diverge in practices and motivations. This paper provides a comparative analysis of the four policies, focusing on strategies, aid volumes and allocation. The analysis reveals that while Hungary’s approach has diverged the most from the other three, all four are now developing distinct donor profiles. International development policy has become relatively politicized in Hungary and Poland, where governments have used it to promote economic nationalism, ideology and security goals, and have resisted socialization pressures arising from membership in the EU and the OECD’s Development Assistance Committee. In the Czech Republic and Slovakia however, the policy had little political salience, leaving space for aid bureaucracies to shape it according to the norms promoted by these organizations.

Impacts of Climate Change and Adaptation Strategies for Rainfed Barley Production in the Almería Province, Spain

Mediterranean water-stressed areas face significant challenges from higher temperatures and increasingly severe droughts. We assess the effect of climate change on rainfed barley production in the aridity-prone province of Almería, Spain, using the FAO AquaCrop model. We focus on rainfed barley growth by the mid-century (2041–2070) and end-century (2071–2100) time periods, using three Shared Socio-economic Pathway (SSP)-based scenarios: SSP1-2.6, SSP2-4.5, and SSP5-8.5. Using the paired t-test, Spearman and Pearson correlation coefficient, Root Mean Squared Error, and relative Root Mean Squared Error, we verified AquaCrop’s ability to capture local multi-year trends (9 or more years) using standard barley crop parameters, without local recalibration. Starting with a reference Initial Soil Water Content (ISWC), different soil water contents within barley rooting depth were modelled to account for decreases in soil water availability. We then evaluated the efficiency of different climate adaptation strategies: irrigation, mulching, and changing sowing dates. We show average yield changes of +14% to −44.8% (mid-century) and +12% to −55.1% (end-century), with ISWC being the main factor determining yields. Irrigation increases yields by 21.1%, utilizing just 3% of Almería’s superficial water resources. Mulches improve irrigated yield performances by 6.9% while reducing irrigation needs by 40%. Changing sowing dates does not consistently improve yields. We demonstrate that regardless of the scenario used, climate adaptation of field barley production in Almería should prioritize limiting soil water loss by combining irrigation with mulching. This would enable farmers in Almería’s northern communities to maintain their livelihoods, reducing the province’s reliance on horticulture while continuing to contribute to food security goals.

Carbon nanotubes: a novel innovation as food supplements and biosensing for food safety.

Recently, nanotechnology has emerged as an extensively growing field. Several important fabricated products including Carbon nanotubes (CNTs) are of great importance and hold significance in several industrial sectors, mainly food industry. Recent developments have come up with methodologies for the prevention of health complications like lack of adequate nutrition in our diet. This review delves deeper into the details of the food supplementation techniques and how CNTs function in this regard. This review includes the challenges in using CNTs for food applications and their future prospects in the industry. Food shortage has become a global issue and limiting food resources put an additional burden on the farmers for growing crops. Apart from quantity, quality should also be taken into consideration and new ways should be developed for increasing nutritional value of food items. Food supplementation has several complications due to the biologically active compounds and reaction in the in vivo environment, CNTs can play a crucial role in countering this problem through the supplementation of food by various processes including; nanoencapsulation and nanobiofortification thus stimulating crop growth and seed germination rates. CNTs also hold a key position in biosensing and diagnostic application for either the quality control of the food supplements or the detection of contagions like toxins, chemicals, dyes, pesticides, pathogens, additives, and preservatives. Detection such pathogens can help in attaining global food security goal and better production and provision of food resources. The data used in the current review was collected up to date as of March 31, 2024 and contains the best of our knowledge. Data collection was performed from various reliable and authentic literatures comprising PubMed database, Springer Link, Scopus, Wiley Online, Web of Science, ScienceDirect, and Google Scholar. Research related to commercially available CNTs has been added for the readers seeking additional information on the use of CNTs in various economic sectors.

Heavy metals and potential health risk assessment of Lactuca sativa and Daucus carrota from soil treated with organic manures and chemical fertilizer

The large-scale production of food crops with heavy application of chemical fertilizers in the effort to meet the astronomical increase in food demands may be counterproductive to the goal of food security. This study investigated the effect of different soil treatments on the levels of heavy metals (Cr, Cu, Fe, Ni, Pb, and Zn) in two types of vegetables Lactuca sativa (lettuce) and Daucus carrota (carrot). The potential carcinogenic and non-carcinogenic health risks from their consumption were also evaluated. Planting experiment was set up in a randomized block design, with different soil treatments of soil + cow dung (CD), soil + sewage sludge (SS), soil + chemical fertilizer (nitrogen-phosphorus-potassium (NPK)), and untreated soil (UNTRD). The vegetables were harvested at maturity, washed with distilled water, and subjected to an acid digestion process before the levels of heavy metals were measured by inductively coupled plasma spectrometry (ICP-MS). The mean concentrations of the metals in the vegetables across all treatments were below the maximum permissible limits. The pattern of heavy metal accumulation by the vegetables suggested that the lettuce from SS treatment accumulated higher concentrations of heavy metals like Cr (0.20 mg/kg), Cu (3.91 mg/kg), Ni (0.33 mg/kg), and Zn (20.44 mg/kg) than carrot, with highest concentrations of Fe (90.89 mg/kg) and Pb (0.16 mg/kg) recorded in lettuce from NPK treatment. The bioaccumulation factor (BAF) showed that lettuce, a leafy vegetable, has bioaccumulated more heavy metals than carrot, a root vegetable. The BAF was generally below the threshold value of 1 in both vegetables, except in lettuce from NPK and CD treatments and carrot from NPK treatments, with BAF values of 1.6, 1.69, and 1.39, respectively. The cancer risk assessment factors were well below the unacceptable maximum range of 10−4 suggesting that consuming these vegetables might not expose an individual to potential risk of cancer development. The hazard quotient estimations were below the threshold values of 1 for all heavy metals; however, the hazard index (HI) values of 1.27 and 1.58 for lettuce from NPK and SS treatments indicate a potential non-carcinogenic health risk to consumers from intake of all the heavy metals.

International military-space cooperation of Ukraine: legal aspects

Outer space acts as a tremendous resource for the security and defence of a country and the protection of its citizens. Ukraine, despite having to deal with Russia’s full-scale armed aggression, is gradually restoring and building up its space capabilities through cooperation with partner countries. International cooperation in the military and space spheres is manifested as a whole through bilateral treaties on military geography, exchange of various kinds of information that has been obtained through space activities. The space origin of many types of data is no longer unusual and has long been used in the management of military forces. The article is devoted to the modern issues of legal aspects of international military-space cooperation of Ukraine. The research enlightens the importance of legal regulation in the field of space activities to ensure national security and emphasizes the role of legislation in the organization and regulation of space activities, as well as the importance of global partnership and cooperation in achieving space security goals. In the context of the war in Ukraine, there is a need to strengthen international cooperation. Also, it is necessary to expand government-funded military space endeavors and develop a coherent plan for the development of military space cooperation aimed at ensuring national defence interests with allied countries. In addition, the most important activities along this path are strengthening interdepartmental coordination between government agencies involved in space activities, improving the legal framework and elevating the qualifications of space industry and military specialists through the reasonable application of international best practices and advanced experience.

Security Analysis of the Consumer Remote SIM Provisioning Protocol

Remote SIM provisioning (RSP) for consumer devices is the protocol specified by the GSM Association for downloading SIM profiles into a secure element in a mobile device. The process is commonly known as eSIM, and it is expected to replace removable SIM cards. The security of the protocol is critical because the profile includes the credentials with which the mobile device will authenticate to the mobile network. In this paper, we present a formal security analysis of the consumer RSP protocol. We model the multi-party protocol in applied pi calculus, define formal security goals, and verify them in ProVerif. The analysis shows that the consumer RSP protocol protects against a network adversary when all the intended participants are honest. However, we also model the protocol in realistic partial compromise scenarios where the adversary controls a legitimate participant or communication channel. The security failures in the partial compromise scenarios reveal weaknesses in the protocol design. The most important observation is that the security of RSP depends unnecessarily on it being encapsulated in a TLS tunnel. Also, the lack of pre-established identifiers means that a compromised download server anywhere in the world or a compromised secure element can be used for attacks against RSP between honest participants. Additionally, the lack of reliable methods for verifying user intent can lead to serious security failures. Based on the findings, we recommend practical improvements to RSP implementations, future versions of the specification, and mobile operator processes to increase the robustness of eSIM security.

Evaluating the status of information security management in faculty libraries: a case study of Allameh Tabatabai University

ABSTRACT Aim This study aims to evaluate the status of Information Security Management in Faculty Libraries at Allameh Tabatabai University, Tehran, Iran. This study is based on the standard of ISO/IEC 27,002. Method The research method is a descriptive survey. Data was collected through a researcher-made questionnaire based on the ISO/IEC standard 27,002 which includes 11 main indicators and 39 sub-components. The statistical population of this study is 45 main and middle managers of faculties’ libraries of Allameh Tabatabai University located in Tehran (Faculties of Law, Psychology and Educational Sciences, Management and Accounting, Physical Education, Literature and Foreign Languages, Communication Sciences, Economics, Social Sciences, Mathematical and Computer Sciences). Due to the limited statistical population, sampling was not performed. Data analysis was done using descriptive statistics, inferential, and SPSS software. Findings The average score of information security management performance in the faculty libraries of Allameh Tabatabaei University located in Tehran according to ISO/IEC27002 is above average. Examination of the average scores of performance evaluation indicators of faculty libraries of Allameh Tabatabai University showed that four indicators including Information Security Management Policy, Information Security Incident Management, Cryptography, and Security Supplier Relationships are not in a favorable situation and need attention from the relevant managers. In other indicators, the performance of faculty libraries is at the desired level. Conclusion The results show a desirable level of information security management in the faculty libraries of Allameh Tabatabai in Tehran. However, some indicators, such as Information Security Policies, Information Security Incident Management, Cryptography, and Supplier Relationships, are still weaker. Therefore, to achieve security goals some suggestions are provided.

Pet Attachment and Animal Abuse in Human Relationships with Pets as Inspiration for Digital Artworks

Humans and animals have coexisted for a long time with mutual benefits to one another. Relationships between species can create a balanced relationship for the survival of living things on earth. Attachment is an emotional relationship formed by individuals with other individuals who are considered stronger during their lives. Attachment will tend to encourage individuals to trigger closeness through contact and sad reactions due to separation. Individuals have the goal of seeking security and comfort in attachment. Human attachment to pets includes emotional, psychological, and physical interactions that will develop into a good mutual relationship. In attachment relationships, the role of empathy, attachment and anthropomorphism (the human tendency to assign characteristics, feelings and behaviors to non-human species) can influence the level of concern for pet welfare. Lack of empathy, attachment and anthropomorphism can lead to lower levels of care for animals, which may lead to neglect and abuse. Animal abuse is deliberate and repeated behavior with the aim of causing physical or psychological suffering to animals. Physical or psychological suffering in detail includes suffering and misery as well as the onset of pain and death of the animal.

OPTIMASI OPTIMASI PROSES PEMBERSIHAN BERAS: STRATEGI TERAPAN UNTUK PENINGKATAN KUALITAS HASIL PERTANIAN

This community service activity (PKM) aims to introduce and train the community to process their rice harvests using appropriate technology, in the form of a grain peeling machine. The main target of this PKM activity is the people of the Jaya Mandiri Farmers Group in Batu Layang Village RT.04/RW.15, North Pontianak District, who still have limited means for their agricultural activities. The methods applied in this PKM activity are science and technology diffusion, socialization, and active community participation. So that with this PKM activity, the community has gained knowledge and skills in processing their post-harvest rice products, and it is hoped that this can help overcome their productivity problems due to limited agricultural facilities. Cleaning rice not only aims to remove empty grains, dirt and other foreign objects, but also increases the selling value per unit weight, increases the efficiency of drying and processing post-harvest products and extends shelf life. The working principle of the automatic rice cleaning tool is that when the rice is in the main reservoir, it then goes down through a small gap so that when it comes down it is cleaned with a fan so that the dirt stuck to the rice is blown away and the clean rice enters the reservoir section. The construction of this rice cleaning machine is divided into a hoper as a place to input rice, a crankshaft system, while the drive system consists of an electric motor, pulley, belt, pegs, bearings. With this device, the process of cleaning rice can be carried out simply and easily, and the process time, namely cleaning time, is shorter. With a shorter processing time, the production rate per unit time becomes greater. Improving the quality of agricultural products is very important in supporting food security and farmer welfare. One of the key aspects in ensuring the quality of agricultural products is the post-harvest processing process, especially the rice cleaning process. In this context, this research aims to optimize the rice refining process through the implementation of effective applied strategies. This study was conducted through a comprehensive series of laboratory experiments and field tests. Refining methods involving a combination of traditional and innovative technologies were evaluated to find the most efficient strategy for improving rice quality. The research results show that the use of a combination of certain technologies can increase the efficiency of rice cleaning, as well as reduce yield losses and increase the selling value of the product. This research makes a significant contribution to the development of agricultural practices that are sustainable and oriented towards quality results. These findings have direct implications for farmers in increasing the competitiveness of their products in local and global markets, as well as in supporting government efforts to achieve national food security goals.

Enhancement of the Nutritional Composition and Antioxidant Activities of Fruit Pomaces and Agro-Industrial Byproducts through Solid-State Fermentation for Livestock Nutrition: A Review

The abundance of fruit waste from the food industry and wineries, particularly peels, seeds, and other fruit pomace throughout the year, could lead to health and environmental hazards if not channelled into productive areas. Improving or transforming these waste products for better use in other vital sectors could be achieved via solid-state fermentation (SSF) since most waste products are solid. One such productive and important area is the feeding of livestock, which will guarantee millennium food security goals for many nations of the world. The nutritional and antioxidant composition of abundantly available fruit pomace and agro-industrial byproducts could be improved via solid-state fermentation for overall livestock productivity. They contain substantial dietary fibre, protein, and phenolic compounds; hence, improving them via fermentation could serve the livestock industry in dual capacities, including nutraceutical and conventional feedstuff. This review seeks to provide reinforcing evidence on the applicability and impact of fruit pomaces on livestock nutrition. The significant nutrient improvements, beneficial outcomes in feeding trials, and inconsistencies or areas of research gap were also explored.

Transforming Arid and Semi-Arid Areas to be Food Secure: The Role of Small-Scale Irrigation Projects

The primary aim of this research was to evaluate the contribution of irrigation-based initiatives towards ensuring food security. The specific objectives encompassed assessing the role of labor within small-holder irrigation projects in bolstering food security, analyzing the impact of external donor assistance on food security outcomes within these projects, and appraising the extent of governmental backing for small-holder irrigation endeavors in the pursuit of food security goals. Employing a descriptive survey methodology, the study was conducted within various small-holder irrigation projects. The research population consisted of 1303 members affiliated with the irrigation schemes, alongside 12 agricultural officers. Utilizing a simple random sampling technique, two agricultural extension officers were selected from the irrigation schemes, while a stratified sampling approach identified 66 irrigation scheme members for participation in the study. Data collection primarily relied on the administration of questionnaires. Findings revealed that the majority of farmers predominantly relied on their labor or that of family members, with minimal utilization of hired labor observed in small-scale irrigation ventures. Consequently, labor scarcity emerged as a notable challenge within these projects. Furthermore, the study highlighted that a significant proportion of small-holder irrigation initiatives benefited from external donor support. To address labor shortages, the research suggested incentivizing specialized labor while recommending collaborative efforts among farmers to engage specialists in crop management, thereby enhancing crop productivity within the schemes.

Optimization of land use to accommodate nutritional transformation of food systems: a case study from the Beijing–Tianjin–Hebei region

The transformation and reconstruction of China’s food system not only faces many risks, such as the unceasing growth of food consumption on the demand side and the structural imbalance of dietary nutrition, but also must address serious challenges, such as constraints of resources, environment, and production capacity on the supply side. The optimal allocation of land use structure is an important method to realizing a transformation of sustainable food systems, achieving the goal of nutrition security, and guiding coordinated spatial development. This study takes the Beijing–Tianjin–Hebei region as an example, analyzing the development trends of the region’s dietary nutrition structure clarifies the objectives for improving dietary nutrition. This study uses comprehensive optimization model and dynamic land system model, exploring land use optimization schemes under different nutritional goals and development scenarios. The result show that the dietary structure in the Beijing–Tianjin–Hebei region is transitioning from “food based” to “intake balance” and gradually evolved to “intake diversity,” with the main objectives being to maintain stable calorie intake while moderately increasing protein intake and reducing fat intake. Achieving this goal will gradually increase demand for cultivated land and intensify spatial competition for land use. However, by optimizing land use allocation, it is possible to free up more spatial resources to balance economic development and ecological protection and reduce land use fragmentation, thereby significantly enhancing regional economic benefits and the value of ecosystem services based on improvements in dietary nutrition.

Roadmap for National Adoption of Blockchain Technology Towards Securing the Food System of Qatar

The national adoption of any technology involves the tight cooperation between the government and the key players involved in the sector of significance. This study highlights a road map toward blockchain technology (BCT) adoption and how it can catalyze better collaboration between the national authorities who play a vital role in securing food systems. The study discusses novel organizational and management concepts to blockchain-based digital governance and lays the foundation for future research. The methodology involves a combination of a systematic review and field research with officials of Qatar’s Food Security Program. As a result of analysing the case of Qatar, this paper analyzes the key features of both the BCT and the national food security goals of Qatar and investigates the technology–strategy fit. The outcomes include a blockchain collaboration matrix, “Technology Adoption and Stakeholder Effect” Matrix, and mapping the national strategies of Qatar Food Security to the capabilities of blockchain technology. Finally, this work concludes by providing concrete suggestions to help facilitate blockchain adoption within the national IT infrastructure, for better traceability and transparency in the food system.

Authentication, Authorization, Access Control, and Key Exchange in Internet of Things

The Internet of Things (IoT) is a dynamic network of devices and infrastructure supporting instances composed to platforms being based on cloud/fog and blockchain technologies. Its intervention in more and more sensitive areas requires IoT entities (devices and platform instances) to communicate with each other via secure channels generally established by using cryptographical methods. This needs an authentic key exchange, which in turn requires an authentication process. Moreover, it has to be ensured that client entities can access only authorized services provided by authorized server entities. Additionally, requirements specifically introduced by IoT complicate realizing these security goals even more. This article introduces a novel approach providing authentication, authorization, access control, and key exchange in instance-to-instance, device-to-instance, and device-to-device communications to handle cloud/fog-based and blockchain-based platforms. In contrast to related work, realizations of these security goals are not disjunct processes and are integrated with each other in our approach combining zero-knowledge and identity-based schemes while meeting the IoT security requirements. Thus, it does not require any public data pre-distribution or secret pre-sharing between communicating entities, and no entity has to hold any device-specific or instance-specific data to be used for authentication or authorization. While supporting the autonomous character of IoT, our approach is independent of application and platform types without requiring additional components or procedures. Moreover, it is resistant to active man-in-the-middle attacks and does not include costly cryptographic operations. This article also demonstrates the high performance of our approach with regard to multiple affecting factors.

FROM TRADITIONAL TO “SMART” AGRICULTURE: ADVANTAGES, CHALLENGES AND PROSPECTS OF DIGITIZATION

Eter Kharaishvili E-mail: eter.kharaishvili@tsu.ge Doctor of Economics Sciences, Professor of Ivane Javakhishvili Tbilisi State University Tbilisi, Georgia https://orcid.org/0000-0003-4013-7354 Paata Koguashvili E-mail: paata_koguashvili@hotmail.com Doctor of Economics Sciences, Professor of Georgian Technical University Tbilisi, Georgia https://orcid.org/0009-0009-8597-3103 Nino Shengelia E-mail: ninoshengelia@gmail.com PhD Students of Georgian Technical University Tbilisi, Georgia https://orcid.org/0009-0003-4099-1603 Abstract: The article emphasizes the importance of the formation of "smart" agriculture in achieving the goals of food security. Digital transformation is seen as the basis for the modernization and progress of agriculture. The advantages of digitization in agriculture are analyzed, the challenges related to the introduction of digital technologies are presented. The paper evaluates the period of transformation from traditional to "smart" agriculture, their advantages and disadvantages are identified through a comparative analysis of traditional and "smart" farms. One of the main issues in the process of digital transformation is the search for effective ways to transition from traditional to "smart" agriculture. By justifying the relevance of digitization, the question is answered: traditional agriculture or "smart" agriculture? Based on statistical data and facts, the development trends of "smart" agriculture are analyzed, its market value is estimated. Taking into account the growth rate of the global digital transformation market, forecast indicators for the period up to 2030 are presented. The paper provides conclusions on the advantages and challenges of "smart" agriculture, offers recommendations on ways to overcome these challenges and prospective directions of development. Keywords: Traditional Farming, "Smart" Farming, Advantages of Digitization, Challenges of Digital Transformation, Perspectives. JEL classification: Q1; O1; O3.

EPREKM: ElGamal proxy re‐encryption‐based key management scheme with constant rekeying cost and linear public bulletin size

SummaryA vast body of literature is filled with many key management schemes constructed using different cryptographic primitives. They aim toward either security goals or improvement in performance efficiency. However, the key management schemes based on proxy re‐encryption suffer from massive communication and computational costs. We propose an ElGamal proxy re‐encryption‐based construction for the key management scheme to resolve this. The proposed scheme involves constant computational and communication costs in rekeying operations and linear public bulletin size. We achieve essential security requirements of forward and backward secrecy in this scheme. The scheme is also secure against the collusion attack. In addition, we address the importance of adequately managing missed rekeying updates for offline users. The existing schemes trivially keep track of each rekeying message on the public bulletin board, which increases the size of the public bulletin with every join/leave operation. However, the proposed scheme uses the public bulletin board so that the handling of offline users is built into the scheme itself, which manages it efficiently. Also, the public bulletin size in the proposed scheme is not dependent on the number of rekeying operations but linear in the number of users.

Efficient public-key searchable encryption against inside keyword guessing attacks for cloud storage

Cloud storage offers data users relief from cumbersome management tasks and enhances overall efficiency. However, while it brings convenience, there is also the risk of privacy breaches. To address this, public-key encryption with keyword search (PEKE) presents a solution that balances efficiency, convenience, and security in the context of cloud storage. Nevertheless, PEKS is vulnerable to inside keyword guessing attacks and algorithm substitution attacks, posing a serious threat to its deployment. Cryptographic reverse firewall technique randomizes incoming messages to effectively defend against both types of attacks mentioned earlier through a gateway. However, this approach requires the gateway to store a random number for each keyword, increasing storage costs and potentially exposing keyword information. In response, we propose an improved scheme that inherits the remarkable properties of the method based on cryptographic reverse firewall. Additionally, the proposed scheme eliminates the need for gateways to store random numbers, reducing the management and storage burdens and supports multiple keywords for one document, a feature more aligned with real-world applications. Furthermore, we prove the security of the scheme, which achieves the same security goals as the existing scheme. Finally, we analyze the scheme s efficiency through theoretical analysis and performance evaluation, which demonstrates its efficiency.

Ukraine: The Balance of Resources and the Balance of Resolve

The Russia–Ukraine war is not approaching stalemate but remains dynamic and unpredictable. The balance of resources favours the West: its economic superiority over Russia is much greater than during the Cold War. But the balance of resolve favours Russia: it is mobilising its capacity more effectively than the coalition of open democracies that supports Ukraine. The West needs a geo-economic strategy to harness its inherent strength to security goals. It should do three things: mobilise military–industrial production; move towards a general prohibition on trade with Russia with few exceptions; and confiscate the $300 billion in Russian central-bank assets frozen in Western financial systems. Given the stakes of the war, unfounded fears of adverse consequences should not deter Western countries from taking these steps.