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Saturday, 19 October 2013

Wireless Security Basics



In this lesson, you’ll learn some of the basics of Wi-Fi security. We’ll also share our recommendation on which type you should choose – eliminating the guesswork and helping you keep your network as secure as possible.

WHAT ARE THE TYPES OF WIRELESS SECURITY?


There are several types of wireless security that you’ll come across– here’s a quick rundown on the details.

WEP

Wired Equivalent Privacy, aka WEP, is the grandfather of wireless security types, dating back to 1999 (an eternity in the world of technology!). When a client (like your laptop or iPad) connects to a WEP-protected network, the WEP key is added to some data to create an “initialization vector”, or “IV” for short. For example, a 128-bit hexadecimal key is comprised of 26 characters from the keyboard (totaling 104 bits) combined with a 24-bit IV. When a client goes to connect to an AP, it sends a request to authenticate, which is met with a challenge reply from the AP. The client encrypts the challenge with the key, the AP decrypts it, and if the challenge it receives matches the original one it sent, the AP will authenticate the client.

This may sound secure, but there was room in this scheme for an exploit to be discovered. The risk presents itself when a client sends its request to the access point– the portion containing the IV is transmitted wirelessly in clear-text (not encrypted). In addition, the IV is simple compared to the key, and when there are several clients using the same WEP key on a network, IVs have an increased probability of repeating. In a busy environment, a malicious user wishing to gain access to a network utilizing WEP security can passively eavesdrop and quickly collect IVs. When enough IVs have been collected, the key becomes trivial to decrypt.

Clearly, WEP is not the correct choice for securing your network, and in light of this, other types of wireless security were created.  

WPA

Wi-FI Protected Access (WPA) was ratified by the Wi-Fi Alliance in 2003 as a response to the insecurities that were discovered in WEP. This new security standard, the Temporal Key Integrity Protocol (TKIP), included several enhancements over WEP, including a new message integrity check nicknamed “Michael.”

While Michael offered a great deal of improvement over the old way of securing networks, there was still some worry about some security issues with using a similar (though much stronger) implementation.

WPA2

The concerns about Michael led to WPA2’s introduction in 2004. At the center of WPA2 is its use of a security protocol based on Advanced Encryption Standard (AES), the U.S. Government’s preferred choice of encryption.

As it stands now, the only people who should still be using TKIP on a wireless network are those who are dealing with hardware that is rated for 802.11g only.

WPS

In 2007, a new security method – Wi-Fi Protected Setup (WPS) – began to show up on wireless access points. With this type of security, a user is able to add new devices to their network by simply pushing a button (within administration software or physically on the router) and then typing in an 8-digit PIN number on the client device. The PIN feature acts as a sort of shortcut for entering in a longer WPA (Wi-Fi Protected Access) key. The basic idea behind WPS is that having physical access to the AP to hit a button and reading a sticker would provide a more secure implementation of Wi-Fi authentication. Everything was well and good in the WPS world, until last winter, when a security researcher discovered the Achilles Heel in the implementation. Here’s how it works:

The eighth and final digit of the PIN number is a checksum, which is used to make sure the 7 digits that matter don’t get corrupted. From these 7 digits, we can see that there are 10,000,000 possibilities (since each of the 7 digits can be 0-9, with repeats allowed). This is still a pretty huge amount of possibilities, and alone could arguably still be considered quite safe — but there’s a flaw in the checking process. When a PIN is being examined by the AP, the first 4 digits (10,000 possibilities) are checked separately from the last 3 digits (1,000 possibilities). This translates into a malicious user only needing to make at most 11,000 guesses, which a computer can handle in a matter of hours!

As you can see, if you or someone you know is currently using WPS on an access point, you should disable the feature ASAP.

OUR RECOMMENDATION

If your access point or clients are only capable of using WEP, it’s time for you to look at upgrading your technology, for the sake of increased security– not to mention increased throughput speeds on newer devices.

Right now, the best security for your Wi-Fi network is WPA2 with WPS disabled. Using this security combination provides the most secure Wi-Fi network possible today, and gives you the peace of mind you need to “set it and forget it.”

Besides, do you really want to trust a single button to provide all the security for your network? If WPA2 with WPS disabled ever becomes vulnerable, we’ll be sure and keep you updated on the adjustments you should make to remain secure.

Source: metageek

Saturday, 22 June 2013

CLOUD COMPUTING: BASIC CONCEPTS


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Cloud Computing – The technology of distributed data processing in which some scalable information resources and capacities are provided as a service to multiple external customers through Internet technology.

Cloud computing concept includes all of the following concepts:

IaaS (Infrastructure as a Service) – A computer infrastructure, typically presented in the form of virtualization. Is a service within the concept of cloud computing.

PaaS (Platform as a Service) – An integrated platform for the development, deployment, testing and support of web-applications. Presented as a service on the basis of the concept of “cloud hosting“. 

SaaS (Software as a service) – Is the business model of software license, which involves the development and support of the software vendor. Customers also have the opportunity of paid use of it, usually through the Internet.

DaaS (Desktop as a Service) – Another business model license the software, which is a slightly improved model of SaaS, mostly involving the use of multiple services at the same time necessary to complete the work. Was first introduced in the early 2000s.

In addition to the above within the concept of cloud computing there are also common notion Data as a service and Everything as a service respectively. Both concepts show that, through the World Wide Web using Cloud Computing, can meet any requirements in the processing of information. This is the main advantage of cloud computing in the IT-based business solutions.


Sunday, 16 June 2013

What is Intrusion Detection System? How it works ?

This is a post which i stared learning recently so sharing my little knowledge so intrusion detection system (IDS) is basically used for monitoring the network, it detects intruders; that is, unexpected, unwanted or unauthorized people or programs on network.



An intrusion detection system has a number of sensors that is used to detect unwanted or unexpected flow of network traffic, the major sensors as follows:



  • A sensor monitor log files

  • A sensor monitor TCP ingoing or outgoing connections


    How Intrusion Detection System Works?

    Intrusion detection system works by collecting information and then examining it.IDS collects data from it sensors and analyze this data to give notice to the system administrator about malicious activity on the network.

  • An intrusion detection system can be run manually but most IT administrators find it easier to automate the system checks to ensure that nothing is accidentally overlooked.

  • We can mainly categorize an IDS into two type:

    1. NIDS (Network Intrusion Detection Systems).
    2. HIDS (Host Intrusion Detection Systems)

    There is still a question, why we use IDS if there is firewall to perform these tasks, Firewall is used to stop unwanted traffic from entering or leaving the internal enterprise network, where as the IDS is deployed to monitor traffic in vital segments in the network, generating alerts when an intrusion is detected.

    A firewall has got holes to let things through, without it you wouldn't be able to access the Internet or send or receive emails, there are different ways to bypass or cheat a firewall.

    Snort is an excellent open source Network Intrusion Detection System, OSSEC is an Open Source Host-based Intrusion Detection System.

    Below is an an overview of the basic architecture as well as practical examples of how to customize Open Source Host-based Intrusion Detection System to manage logging from your infrastructure and applications.

  • Video On Intrusion Detection System

    source:DARKSITE

    Monday, 13 May 2013

    GSM: Network Architecture

    The GSM technical specifications define the different entities that form the GSM network by defining their functions and interface requirements.
     
    The GSM network can be divided into four main parts:
    • The Mobile Station (MS).
    • The Base Station Subsystem (BSS).
    • The Network and Switching Subsystem (NSS).
    • The Operation and Support Subsystem (OSS).
    The architecture of the GSM network is presented in figure 1.










    Mobile Station:
    A Mobile Station consists of two main elements:
    • The Subscriber Identity Module (SIM): It is protected by a four-digit Personal Identification Number (PIN). In order to identify the subscriber to the system, the SIM card contains amongst others a unique International Mobile Subscriber Identity (IMSI). User mobility is provided through maping the subscriber to the SIM card rather than the terminal as we done in past cellular systems.
    • Mobile equipment/terminal (ME): There are different types of terminals (MN) distinguished principally by their power and application:
      • `fixed' terminals mainly installed in cars. Their maximum allowed output power is 20W
      • portable terminals can also be installed in vehicles. Their maximum allowed output power is 8W.
      • handheld terminals; their popularity is owed to their weight and volume, which is continuously decreasing. According to some specification these terminals may emit up to 0.8W. However, as technology has evolved their maximum allowed power ouput is limited to 0.1W.
      •  
    Base Station Subsystem: The BSS provides the interface between the ME and the NSS. It is in charge of the transmission and reception. It may be divided into two parts:
    • Base Station Controller (BSC): It controls a group of BTSs and manages their radio ressources. A BSC is principally in charge of handoffs, frequency hopping, exchange functions and power control over each managed BTSs.
    • Base Transceiver Station (BTS) or Base Station: it maps to transceivers and antennas used in each cell of the network. It is usually placed in the center of a cell. Its transmitting power defines the size of a cell. Each BTS has between 1-16 transceivers depending on the density of users in the cell.
    NSS: Its main role is to manage the communications between the mobile users and other users, such as mobile users, ISDN users, fixed telephony users, etc. It also includes data bases needed in order to store information about the subscribers and to manage their mobility. The different components of the NSS are described below.
    • MSC: the central component of the NSS. The MSC performs the switching functions of the network. It also provides connection to other networks.
    • GMSC: A gateway that interconnects two networks: the cellular network and the PSTN. It is in charge of routing calls from the fixed network towards a GSM user. The GMSC is often implemented in the same machines as the MSC.
    • HLR: The HLR stores information of the suscribers belonging to the coverage area of a MSC; it also stores the current location of these subscribers and the services to which they have access. The location of the subscriber maps to the SS7 address of the Visitor Location Register (VLR) associated to the MN.
    • VLR: contains information from a subscriber's HLR necessary to provide the subscribed services to visiting users. When a subscriber enters the covering area of a new MSC, the VLR associated to this MSC will request information about the new subscriber to its corresponding HLR. The VLR will then have enough data to assure the subscribed services without needing to ask the HLR each time a communication is established. The VLR is always implemented together with a MSC; thus, the area under control of the MSC is also the area under control of the VLR.
    • Authentication Center (AuC): It serves security purposes; it provides the parameters needed for authentication and encryption functions. These parameters allow verification of the subscriber's identity.
    • Equipment Identity Register (EIR): EIR stores security-sensitive information about the mobile equipments. It maintains a list of all valid terminals as identified by their International Mobile Equipment Identity (IMEI). The EIR allows then to forbid calls from stolen or unauthorized terminals (e.g, a terminal which does not respect the specifications concerning the output RF power).
    • GSM Interworking Unit (GIWU): The GIWU provides an  interface to various networks for data communications. During these communications, the transmission of speech and data can be alternated.
    Operation and Support Subsystem (OSS): It is connected to components of the NSS and the BSC, in order to control and monitor the GSM system. It is also in charge of controlling the traffic load of the BSS. It must be noted that as the number of BS increases with the scaling of the subscriber population some of the maintenance tasks are transferred to the BTS, allowing savings in  the cost of ownership of the system.
     
     
    Geographical areas
    A cell, as identified by its Cell Global Identity (CGI) number, maps to the radio coverage of a BTS. Similarly an LA as identified by its Location Area Identity (LAI) number , is a cluster of cells served by a single MSC/VLR. A group of LA under the control of the same MSC/VLR defines the MSC/VLR area. A Public Land Mobile Network (PLMN) is the area served by one network operator.
     
     
    Network operations
    In this paragraph, the description of the GSM network is focused on the differents functions to fulfil by the network and not on its physical components. In GSM, five main functions can be defined:
    • Transmission: of data and signaling. Not all the components of the GSM network are strongly related with both types of types of Tx. While the MSC, BTS and BSC, among others, are involved with data and signaling, components such as  HLR, VLR or EIR registers, are only concerned with signaling.
    • Radio Resources Management (RRM).
    • Mobility Management (MM).
    • Communication Management (CM).
    • Operation, Administration and Maintenance (OAM).

     Radio Resources Management (RRM)
    The role of the RR function is to establish, maintain and release communication links between mobile stations and the MSC. The elements that are mainly concerned with the RR function are the MN and the BTS. However, since the RR component performs connection management also during cell handoffs,  it also affects the MSC  which is the handoff management component.
    The RR is also responsible for the management of frequency resources as well as varying radio interface conditions. Main component operations are:
    • Channel assignment, change and release.
    • Handoff
    • Frequency hopping.
    • Power-level control.
    • Discontinuous transmission and reception.
    • Timing advance.

     Handoff
    The user movements may result a change in the channel/cell, when the quality of the communication is degrading; this is known as handoff. Handoffs occur between:
    • between channels within a cell
    • between cells controlled by the same BSC
    • between cells under the same MSC but controlled by different BSCs
    • between cells controlled by different MSCs.
    Handoffs are mainly controlled by the MSC. However to avoid unnecessary signalling, the first two types of handoffs are managed by the respective BSC (thus, the MSC is only notified of the handoff). To perform the handoff the mobile station controls continuously its own signal strengh and the signal strengh of the neighboring cells. The list of cells that must be monitored by the mobile station is given by the base station. Power measurements allow to decide which is the best cell in order to maintain the quality of the communication link. Two basic algorithms are used for handoffs:
    • The `minimum acceptable performance' algorithm. When the quality of the transmission degrades, the power level of the mobile is increased, until the increase of the power level has no effect on the quality of the signal. Upon this link layer hint, a handoff is initiated.

    • The `power budget' algorithm. Here the handoff pre-empts the power increase, to obtain a good SIR.
    Mobility Management (MM) The MM component handles:
    • Location Management: Location is managed through periodicaly or on-demand. At power-on time, the MH signals an IMSI attach. On-demand location updates are signalled when the MN moves to a different PLMN or new location area (LA). The signal is sent to the new MSC/VLR, which forwards it to the subscriber's HLR. Upon authorization in the new MSC/VLR, the subscriber's HLR removes the registration entry of the MN at the old MSC/VLR. If after the update time interval, the MN has not registered, it is then deregistered. On power-off, the MN performs an IMSI detach.
    • security and authentication:  Authentication involves the SIM card and the Authentication Center. A secret key, stored in the SIM card and the AuC together with a ciphering algorithm called A3, are used to authenticate the user. The MN and the AuCcompute a SRES through A3 using the secret key and a nonce generated by the AuC. If the two computed SRES are the same, the subscriber is authenticated. The different services to which the subscriber has access are also checked. Next the a security check is performed in the equipment identity (IMEI). If the IMEI number of the mobile is authorized in the EIR, the mobile station is allowed to connect the network. To assure user confidentiality, the user is registered with a Temporary Mobile Subscriber Identity (TMSI) after its first location update procedure. Enciphering is another option to guarantee a very strong security.

    Communication Management (CM):
    The CM component manages:
    • Call control (CC): it controls call setup, management and tear-down in relation to management of type of service. Call routing is the primary task for this component. To reach a mobile subscriber, a user dials the Mobile Subscriber ISDN (MSISDN) number which includes:
      • a country code
      • a national destination code; this identifies the subscriber's operator
      • a code mapping to the subscriber's HLR.
      • The call is then passsed to the GMSC (if the call is originated from a fixed network) that 'knows' the HLR corresponding to the particular MSISDN number. The GMSC signals the HLR for call routing information. The HLR requests this information from the subscriber's current VLR. This VLR allocates temporarily a Mobile Station Roaming Number (MSRN) for the call. The MSRN number is the information returned by the HLR to the GMSC. It is latter that routes the call through the MSRN number, to the subscriber's current MSC/VLR. In the subscriber's current LA, the mobile is paged.
    • Supplementary Services management: This involves the MN and the HLR.

    • SMS management: Here the GSM network contacts the Short Message Service Center through the two following interfaces:
      • SMS-GMSC for Mobile Terminating Short Messages (SMS-MT/PP). It has the same role as the GMSC.
      • SMS-IWMSC for Mobile Originating Short Messages (SMS-MO/PP).

    Operation, Administration and Maintenance (OAM):
    The OAM component allows the operator to monitor and control the system as well as modify the configuration of the elements of the system. Not only the OSS is part of the OAM, but also the BSS and NSS participate in functions such as:
    • provide the operator with all the information it needs. This information is forwarded to the OSS to control the network.
    • perform self-test tasks in addition to the OAM functions.
    • control of multiple BTSs by the BSS.

    Saturday, 30 March 2013

    Ebook software Engineering by pressman

    So, you want "XYZ" ok... lets start coding.. STOP! Probably, this was the way you were developing some small softwares or program. Software Engineering, talks about engineering a product. It is the application of the knowledge you have to a software. You have to understand the idea behind developing the software, various parameters involved, cost, benefit, quality, reliability etc. The subject includes the software models for developing softwares and project planning ideas with different structures that are being followed in the companies. It makes you understand that just the code for a software would not suffice, you need to plan and implement it in the best way.


    Syllabus


    i) Introduction, What is software engineering?
    ii) Software Development Life Cycle, Requirements Analysis, Software Design, Coding, Testing, Maintenance etc. iii) Software Requirement Specification, Waterfall Model, Prototyping Model, Iterative Enhancement Model, Spiral Model, Role of Management in Software Development, Role of Metrics and Measurement, Problem Analysis, Requirement Specification, Validation, Metrics, Monitoring and Control.
    iv) System Design, Problem Partitioning, Abstraction, Top-down and bottom-up design, Structured Approach, Functional v/s Object-Oriented Approach, Design specification & verification, metrics, Monitoring & Control
    v) Coding, Top-down & Bottom-up, Structured Programming, Information Hiding, Programming Style, Internal Documentation, Verification, Metrics, monitoring & control
    vi) Testing, Levels of Testing- Functional Testing, Structural Testing, Test Plan, Test Cases Specification, Reliability assessment.
    vii) Software Project Management, Cost Estimation, Project Scheduling, Staffing, Software Configuration Management, Quality Assurance, Project Monitoring, Risk Management

    Download -Mediafire link

    Ebook- Programming with java by E.Balaguruswamy



    Java is yet another computer language but with a difference. It is the only language that is purely object-oriented. It is a secure language, making it well-suited for Internet programming. One of the important reasons for Java's success, apart from its object-orientation, is the amazing functionality it adds to the World Wide Web. This book by Balaguruswamy comprehensively covers all aspects of Java language. Beginning with an introduction to the language and its relationship with the Internet and World Wide Web, it explores Java's object¬ oriented features, and then moves on to discuss advanced topics that are unique to Java. The concept of learning by example has been stressed throughout the book. 

    Download Link:

    Deposit files link