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Robust and Low Latency Security Framework for Ieee 802. 11 Wireless Networks

Thesis Info

Access Option

External Link

Author

Junaid, Muhammad

Program

PhD

Institute

National University of Sciences & Technology

City

Islamabad

Province

Islamabad

Country

Pakistan

Thesis Completing Year

2009

Thesis Completion Status

Completed

Subject

Applied Sciences

Language

English

Link

http://prr.hec.gov.pk/jspui/handle/123456789/1964

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727107337

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Wireless Networks call for enhanced confidentiality, integrity and authentication services because of their inherent weakness. ‘Counter Mode Cipher Block Chaining Message Authentication Code Protocol’ (CCMP) has recently been employed to replace flawed ‘Wired Equivalent Privacy’ (WEP) Protocol for the provision of security to IEEE 802.11 wireless local area networks (WLAN). Meanwhile, IEEE 802.11s – draft standard for wireless mesh networks (WMN) – has also proposed to use CCMP. CCMP, a two pass process, introduces considerable latency in multi-hop wireless networks, such as WMN. Increase in latency leads to a decrease in the quality of service for delay sensitive real-time multimedia applications. This research exposes the vulnerability of CCMP against pre- computation time memory trade-off (TMTO) attack and proposes a framework to strengthen the security of WLAN packets using Per-Packet security mechanism. Furthermore, a novel, robust and low latency framework for WMN is also proposed. The architecture of security framework involves introduction of piggyback challenge response protocol for providing data confidentiality and data integrity. Piggyback challenge response protocol offers fresh encryption key for every packet, per-packet authentication and use of secret nonce. Authentication of every packet offers prompt defense against unauthorized access. It is also demonstrated that the security framework is robust against a variety of security attacks. Encrypted and unique nonce provides unpredictability and freshness. Unpredictability prevents pre-computation attack and freshness ensures successful defense against replay attacks. Proposed framework is simulated and its iiperformance is compared with IEEE 802.11i in terms of latency introduced by the security components. For single hop, latency due to the proposed protocol is less than half as compared to CCMP. The improvement in latency becomes more pronounced as the number of hops increase. This novel framework addresses the CCMP deficiencies of high latency and vulnerability against TMTO attack, without compromising any of the security measures implemented in the standard.
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فصل پنجم: آیاتِ استفہام میں فہمِ آخرت

دین کی اصل توحید ہے قرآن کے مطلوب انسان کی زندگی ایک اللہ کی وفادار ہوتی ہے اس کا ہر سجدہ ،ہر امید، ہر اندیشہ، ہر محبت، ہر خوف، ہر دعا ،ہر عبادت صرف اور صرف اللہ کے لئے ہوتی ہے وہ اپنے رب کے ساتھ کسی کو شریک کرنے کا تصور بھی نہیں کر سکتا اللہ کے سوا کوئی رب نہیں ہے وہ واحد و یکتا ہے وہی معبود برحق ہے ۔

اللہ تبارک وتعالیٰ قرآن مجید میں ارشاد فرماتے ہیں:

" اِنَّ اِلٰهَكُم لَوَاحِدٌ "۔[[1]]

"بیشک الہ تم سب کا ایک ہے"۔

قرآن میں بہت سے مقامات پر ہمیں توحید کا بیان ملتا ہے۔اس آیت میں الہ کی بنیادی نوعیت یہ ہے کہ معبود حقیقی سب کا ایک ہی ہے۔ اس میں تعدد کا احتمال نہیں ہے یہ خدائی اور معبودی ہے نہ اس کے سوا کسی کو معبود بنا سکتے ہیں اور نہ ہی کسی اور سے خیر کی توقع کی جا سکتی ہے۔ یہ توحید ہی سب سے پہلی اور سب سے بڑی چیز ہے جو ملت ابراہیم علیہ السلام کی وراثت کی حیثیت سے اس امت مسلمہ کی طرف منتقل ہوئی ہے ۔ اللہ تعالیٰ اپنی ذات و صفات میں یکتاو یگانہ ہے کوئی اس کی برابری کرنے والا نہیں ہے کوئی اسکا ہمسر مسلمان ہونے کے لیے ان تمام عقائد پر ایمان لانا ضروری ہے جن کو ہمیں قرآن میں حکم دیا گیا ہے۔

 ارکان"رکن" کی جمع ہے اور رکن کسی بھی چیز کا اہم جز ہوتا ہے جس کے بغیر وہ مکمل نہیں ہوسکتی ایمان کے چھ ارکان ہیں لہذا اگر ایمان کا ایک رکن بھی ساقط ہو جائے تو انسان مومن نہیں رہتا خواہ وہ لاکھ ایمان کے دعوے کرتا رہے جیسے...

Global Structural Changes and Global Islamic Identity

Globalization is slowly changing life and traditions of many people over the World, dramatically seeking changes in the traditional relationship between the community and people, creating a new sensibility and creativity in relationships between social groups. These changes necessarily require a new social and political model of organization for community, reorganizing and changing the nature of relationship between states.  Effort to protect identity of people usually convey in the form of the fear of the subservient economic, cultural and political position in the process of globalization. This fear frequently produces powerful vibrations indicating the need of integration of social groups with the same or similar cultural identity, what opens up a new dimension of the internal political crisis between government and society. This crisis will produce particularly dramatic changes in Islamic world generating a powerful conflict between state and society in Islamic world, with unpredictable development of relations between Islam and West.

Rheological & Release Characteristics of Drugs of Different Solubilities from Semisolid Matrix Filled in Hard Gelatin Capsule

The re-introduced liquid/semisolid matrix technology, in recent past encompasses filling of hard gelatin capsules for thixotropic system at ambient and thermosoftened system at elevated temperature. Formulations in both of the above systems may contain dissolved or dispersed drugs. In the present work thixotropic gels were prepared using a series of hydrophilic poloxamers (Pluronic/Synperonic L31, L43, L62, L64, L92) of different viscosities and composition of polyoxyethhylene and polyoxypropylenein co-polymers thickened with hydrophilic silicon dioxide (Aerosil®A200) to form gel structure. Model drugs of varying solubilities, isoniazid, metronidazole, paracetamol and mefenamic acid were dispersed in gels of above poloxamers. The gel formulations were filled into hard gelatin capsules via syringe. The rheological characteristics, dispersion stability, and FTIR of the gels with and without drugs were investigated. The gels with drugs were additionally characterized for their release pattern. In preliminary studies, twenty separate gels of poloxamers L31, L64 were thickened with concentrations 1 to 10% w/w of Aerosil® A200 to incorporate isoniazid (unsifted, 10% w/w). Different concentration of Aerosil® A200 affected dispersion stability as well as release of the drug incorporated into gels. All gels were thixotropic and shear thinning. A little change in apparent viscosity on storage upto 30 days was noted. Disperse phase sedimentation was not observed with more viscous poloxamer and with higher concentration of silicon dioxide. Higher concentration of Aerosil® A200 resulted into stronger gel structure between silicon dioxide and poloxamers and thereby, hindered release of drug from a gel. Rheograms of poloxamers, L31 and L64 confirmed their Newtonian behaviour, in contrast to the thixotropic behaviour of all gels made with Aerosil® A200 concentrations (1-10% w/w) and 10% w/w isoniazid. Therefore, ii in-vitro release of highly water soluble drug, isoniazid could be controlled by poloxamer/A200 thixotropic gel system which depended upon concentration of Aerosil® A200, viscosity of poloxamer and the aqueous solubility of drug. In the further work, the effect of selected concentration of Aerosil® A200 (8% w/w) and five liquid poloxamers of different viscosities on release of drugs with characterized particle size (180-250 μm) and of different from semi solid matrix/ thixotropic gel filled into hard gelatin capsules was tested by in-vitro dissolution test. The drugs with different solublities used in this study were isoniazid, metronidazole, paracetamol and mefenamic acid. The interaction of drug in gel formulations was also determined by Fourier transform infrared (FTIR) spectroscopy. The release of drugs from different formulations was related to their aqueous solubility, viscosity of poloxamers, and poloxamer’s polyoxyethylene and polyoxypropylene proportions. In most of the formulations drug remains dispersed over a period of one month depending upon the viscosity of gels. Most of the gels showed little change in apparent viscosity on storage. The apparent viscosity for each gel was found to be dependent on the viscosity of poloxamers from which the gel was prepared. Like in preliminary work, rheograms of five pure poloxamers showed Newtonian behaviour whereas each gel exhibited thixotropic and shear thinning. In-vitro dissolution data of drugs from their respective stable gels followed first order kinetics. No chemical interaction or incompatibilities between drugs and polymers were noted by FTIR. Long term stability studies at International conference on harmonization (ICH) recommended conditions of temperature/relative humidity (30°C/65% RH) over one year revealed that almost all the gels retained their rheological, dispersion stability, release profile and chemical integrity. Thus, the hydrophilic semisolid matrix (gels) made by mixing poloxamer and Aerosil® (A200) was suitable for filling into hard gelatin capsules because of their rheological characteristics. The release of drugs with different solubilities could be modified by using iii poloxamers of different viscosity. Overall present research study demonstrates the effect of silicon dioxide on the microstructure of the gel prepared with various poloxamers which is evident from the rheological studies, FTIR and release pattern of the drugs.