A formal methodology for integral security design and verification of network protocols

We propose a methodology for verifying security properties of network protocols at design level. It can be separated in two main parts: context and requirements analysis and informal verification; and formal representation and procedural verification. It is an iterative process where the early steps are simpler than the last ones. Therefore, the effort required for detecting flaws is proportional to the complexity of the associated attack. Thus, we avoid wasting valuable resources for simple flaws that can be detected early in the verification process. In order to illustrate the advantages provided by our methodology, we also analyze three real protocols

EVALUATION OF NOOTROPIC ACTIVITY OF ACHYRANTHES ASPERA LEAVES EXTRACT IN WISTAR RATS

Objective: The objective of the study was to evaluate the nootropic activity of hydroalcoholic extract of Achyranthes aspera leaves using elevated plus maze and radial arm maze.Methods: Adult Wistar rats were allotted to three groups; Group 1 served as control, Groups 2 and 3 received 200 mg/kg and 400 mg/kg of AA extract, respectively, orally for 2 weeks after which the extent of improvement of memory was assessed.Results: AA showed nootropic activity in both elevated plus maze and radial arm maze. 200 mg/kg of AA extract showed better improvement in learning and memory compared to 400 mg/kg.Conclusions: These results indicate that AA leaves extract clearly exhibited the improvement in learning and memory

The protective effect of Withania somnifera against oxidative damage caused by ethanol in the testes of adult male rats

Background: To investigate the effect of Withania somnifera (WS) in preventing the damage caused by alcohol on testis.Methods: Adult male Wistar rats were divided into 4 groups. Group A - control, Group B - WS200 mg orally, Group C - alcohol 4 g/kg orally, and Group D - WS + alcohol. The sperm parameters were examined. Testicular tissues were examined for biochemical (glutathione [GSH] peroxidase, superoxide dismutase, catalase (CAT), malondialdehyde [MDA]) analysis, and histopathological changes.Results: Biochemical parameters revealed tissue oxidative stress in alcohol group which was evidenced as increase in MDA level and reduction in CAT and GSH activities in testes which was reduced in co-treatment group. WS significantly reduced alcohol-induced sperm shape abnormality and sperm count. The alcohol-induced changes in histopathologic findings were partially reversed by treatment with WS.Conclusion: These observations suggest that the antioxidant property of WS might have contributed for its ability to ameliorate the testicular toxicity caused by alcohol

Content delivery over TLS: a cryptographic analysis of keyless SSL

The Transport Layer Security (TLS) protocol is designed to allow two parties, a client and a server, to communicate securely over an insecure network. However, when TLS connections are proxied through an intermediate middlebox, like a Content Delivery Network (CDN), the standard endto- end security guarantees of the protocol no longer apply. In this paper, we investigate the security guarantees provided by Keyless SSL, a CDN architecture currently deployed by CloudFlare that composes two TLS 1.2 handshakes to obtain a proxied TLS connection. We demonstrate new attacks that show that Keyless SSL does not meet its intended security goals. These attacks have been reported to CloudFlare and we are in the process of discussing fixes. We argue that proxied TLS handshakes require a new, stronger, 3-party security definition. We present 3(S)ACCEsecurity, a generalization of the 2-party ACCE security definition that has been used in several previous proofs for TLS. We modify Keyless SSL and prove that our modifications guarantee 3(S)ACCE-security, assuming ACCE-security for the individual TLS 1.2 connections. We also propose a new design for Keyless TLS 1.3 and prove that it achieves 3(S)ACCEsecurity, assuming that the TLS 1.3 handshake implements an authenticated 2-party key exchange. Notably, we show that secure proxying in Keyless TLS 1.3 is computationally lighter and requires simpler assumptions on the certificate infrastructure than our proposed fix for Keyless SSL. Our results indicate that proxied TLS architectures, as currently used by a number of CDNs, may be vulnerable to subtle attacks and deserve close attention

Integrated diagnostics: proceedings from the 9th biennial symposium of the International Society for Strategic Studies in Radiology

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A gentle introduction to multiparty asynchronous session types

This article provides a gentle introduction to multiparty session types, a class of behavioural types specifically targeted at describing protocols in distributed systems based on asynchronous communication. The type system ensures well-typed processes to enjoy non-trivial properties, including communication safety, protocol fidelity, as well as progress. The adoption of multiparty session types can positively affect the whole software lifecycle, from design to deployment, improving software reliability and reducing its development costs

KyberSlash: Exploiting secret-dependent division timings in Kyber implementations

This paper presents KyberSlash1 and KyberSlash2 – two timing vulnerabilities in several implementations (including the official reference code) of the Kyber Post-Quantum Key Encapsulation Mechanism, recently standardized as ML-KEM. We demonstrate the exploitability of both KyberSlash1 and KyberSlash2 on two popular platforms: the Raspberry Pi 2 (Arm Cortex-A7) and the Arm Cortex-M4 microprocessor. Kyber secret keys are reliably recovered within minutes for KyberSlash2 and a few hours for KyberSlash1. We responsibly disclosed these vulnerabilities to maintainers of various libraries and they have swiftly been patched. We present two approaches for detecting and avoiding similar vulnerabilities. First, we patch the dynamic analysis tool Valgrind to allow detection of variable-time instructions operating on secret data, and apply it to more than 1000 implementations of cryptographic primitives in SUPERCOP. We report multiple findings. Second, we propose a more rigid approach to guarantee the absence of variable-time instructions in cryptographic software using formal methods

towards formal validation of trust and security in the internet of services

Service designers and developers, while striving to meet the requirements posed by application scenarios, have a hard time to assess the trust and security impact of an option, a minor change, a combination of functionalities, etc., due to the subtle and unforeseeable situations and behaviors that can arise from this panoply of choices. This often results in the release of flawed products to end-users. This issue can be significantly mitigated by empowering designers and developers with tools that offer easy to use graphical interfaces and notations, while employing established verification techniques to efficiently tackle industrial-size problems. The formal verification of trust and security of the Internet of Services will significantly boost its development and public acceptance