BASIC SECURITY CONCEPTS in VS .NET

Maker Code 128 in VS .NET BASIC SECURITY CONCEPTS
BASIC SECURITY CONCEPTS
USS Code 128 Reader In Visual Studio .NET
Using Barcode Control SDK for .NET framework Control to generate, create, read, scan barcode image in VS .NET applications.
Cryptographic Primitives
Creating ANSI/AIM Code 128 In Visual Studio .NET
Using Barcode creation for Visual Studio .NET Control to generate, create Code 128C image in .NET framework applications.
Cryptographic systems based on the use of keys can be thought of as analogous to combination locks They involve both an algorithm and a secret value The secret value is the key (analogous to the number that opens the combination lock) and this must be protected from adversaries The cryptographic algorithm can be considered to be analogous to the working of the combination lock The design of the algorithm is expected to be known widely In fact, making the design of the algorithm public can lead to analysis of its weaknesses by the community The security of the system should only depend on the secrecy of the key, and an adversary who desires to break the cryptographic system has to determine the key used to secure communications A basic approach that can be taken by the adversary is to try every key and see which breaks the system based on some information about the system For example, if packets between two nodes are encrypted, then the adversary might have an idea as to the protocol being used, such as TCP or UDP By trying every possible key to decrypt the packets, the adversary will come up with random strings Only a few such strings will t the format associated with a packet belonging to the protocol More information about the data, such as the identity of the parties communicating or the port numbers being used for the communication, could be used to increase the probability of determining the right key being used Such an approach is easy to pursue in wireless systems given the susceptibility of wireless links to eavesdropping, making all traf c going over the network available to the adversaries It is obvious that the effort required for such an attack to be successful is proportional to the length of the key An 8 bit key length implies that there are 28 different keys possible while an 80 bit key length implies that there are 280 different keys possible This is similar to the case of combination locks Even here, longer combinations of keys take longer to break as opposed to smaller combinations, assuming that all possible keys can be tried However, we cannot conclude that longer key length always translates into better security for the system In some cases, there can be other vulnerabilities in the system, including the encryption algorithm, that the adversary could take advantage of For example, it has been shown that the security of WEP (the typical protocol used for securing 80211b) can be broken irrespective of the size of the key used [8] Hence, while key size is important, the evaluation of cryptographic primitives cannot be done solely based on the size of the keys Other factors which are used to evaluate the various cryptographic primitives include:
Code 128 Scanner In .NET Framework
Using Barcode reader for VS .NET Control to read, scan read, scan image in .NET framework applications.
level of security; functionality; methods of operation; ease of implementation; performance
Barcode Creation In Visual Studio .NET
Using Barcode encoder for .NET Control to generate, create bar code image in VS .NET applications.
The level of security afforded could be related to cost A higher level of security could result in the system being secure even against well-funded adversaries Note, though, that the level of security itself is a qualitative measure The functionality would be related to the attributes that can be achieved using the proposed primitive For example, nonrepudiation would need the use of concepts from asymmetric key cryptography
Bar Code Scanner In .NET Framework
Using Barcode decoder for .NET Control to read, scan read, scan image in .NET applications.
22 BASIC CONCEPTS
Code 128 Encoder In C#
Using Barcode encoder for Visual Studio .NET Control to generate, create Code 128 Code Set A image in .NET framework applications.
The method of operation could also be different in order to achieve different functionality For example, asymmetric key algorithms would require different modes when used to ensure con dentiality and nonrepudiation Ease of implementation is another important factor Performance also needs to be considered, especially in ad hoc networks given the resource constraints in such networks It is well known that message digests, which we explain later, need the least amount of resources in terms of memory and computation power, while asymmetric key operations are the most expensive 2221 Attacks in Cryptographic Systems An adversary in any system protected by cryptographic primitives can have several objectives For example, the adversary might aim for the total break whereby he/she obtains the secret keys being used to secure communication A weaker objective of the adversary could be to obtain the ability to decrypt a ciphertext for which he/she has not seen the plaintext1 A still weaker objective could be to be able to distinguish between the encryptions of two plaintexts that the adversary has not seen before A cryptosystem that does not permit distinguishability of ciphertexts is said to be semantically secure Given these goals of the adversary, there can be several types of attacks Note that we consider generic attacks here instead of speci c attacks (such as wormhole or sybil) An assumption here is that the adversary has access to all data transmitted over the ciphertext channel In addition, we assume that the adversary knows all details of the encryption function except the secret keys With these standard assumptions we can have the following types of generic attacks:
ANSI/AIM Code 128 Encoder In .NET
Using Barcode generator for ASP.NET Control to generate, create USS Code 128 image in ASP.NET applications.
Drawing Code 128B In VB.NET
Using Barcode creation for .NET Control to generate, create Code 128 image in .NET applications.
Code 128C Generator In VS .NET
Using Barcode creator for Visual Studio .NET Control to generate, create Code 128 Code Set B image in .NET framework applications.
European Article Number 8 Creation In VS .NET
Using Barcode creator for .NET framework Control to generate, create EAN / UCC - 8 image in Visual Studio .NET applications.
Paint Code 128C In Visual C#.NET
Using Barcode generation for .NET framework Control to generate, create ANSI/AIM Code 128 image in VS .NET applications.
GS1 - 13 Drawer In C#.NET
Using Barcode maker for VS .NET Control to generate, create EAN13 image in .NET framework applications.
European Article Number 13 Recognizer In VS .NET
Using Barcode recognizer for Visual Studio .NET Control to read, scan read, scan image in .NET framework applications.
GS1 128 Encoder In Visual Basic .NET
Using Barcode maker for Visual Studio .NET Control to generate, create GS1 128 image in Visual Studio .NET applications.