mudassirbackup

Author: misamaliraza94

  • Importance of Digital Signature

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    misamaliraza94
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    Out of all cryptographic primitives, the digital signature using public key cryptography is considered as very important and useful tool to achieve information security. Apart from ability to provide non-repudiation of message, the digital signature also provides message authentication and data integrity. Let us briefly see how this is achieved by the digital signature −…

  • Cryptography Digital signatures

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    misamaliraza94
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    Digital signatures are the public-key primitives of message authentication. In the physical world, it is common to use handwritten signatures on handwritten or typed messages. They are used to bind signatory to the message. Similarly, a digital signature is a technique that binds a person/entity to the digital data. This binding can be independently verified…

  • Message Authentication

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    misamaliraza94
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    In the last chapter, we discussed the data integrity threats and the use of hashing technique to detect if any modification attacks have taken place on the data. Another type of threat that exist for data is the lack of message authentication. In this threat, the user is not sure about the originator of the message.…

  • Whirlpool

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    misamaliraza94
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    This is a 512-bit hash function. Applications of Hash Functions There are two direct applications of hash function based on its cryptographic properties. Password Storage Hash functions provide protection to password storage. Data Integrity Check Data integrity check is a most common application of the hash functions. It is used to generate the checksums on…

  • Popular Hash Functions

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    misamaliraza94
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    Let us briefly see some popular hash functions − Message Digest (MD) MD5 was most popular and widely used hash function for quite some years. Secure Hash Function (SHA) Family of SHA comprise of four SHA algorithms; SHA-0, SHA-1, SHA-2, and SHA-3. Though from same family, there are structurally different. RIPEMD The RIPEMD is an…

  • Properties of Hash Functions

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    misamaliraza94
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    In order to be an effective cryptographic tool, the hash function is desired to possess following properties − Design of Hashing Algorithms At the heart of a hashing is a mathematical function that operates on two fixed-size blocks of data to create a hash code. This hash function forms the part of the hashing algorithm.…

  • Cryptography Hash functions

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    misamaliraza94
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    Hash functions are extremely useful and appear in almost all information security applications. A hash function is a mathematical function that converts a numerical input value into another compressed numerical value. The input to the hash function is of arbitrary length but output is always of fixed length. Values returned by a hash function are…

  • Data Integrity in Cryptography

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    misamaliraza94
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    Until now, we discussed the use of symmetric and public key schemes to achieve the confidentiality of information. With this chapter, we begin our discussion on different cryptographic techniques designed to provide other security services. The focus of this chapter is on data integrity and cryptographic tools used to achieve the same. Threats to Data…

  • ElGamal Analysis

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    misamaliraza94
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    In ElGamal system, each user has a private key x. and has three components of public key − prime modulus p, generator g, and public Y = gx mod p. The strength of the ElGamal is based on the difficulty of discrete logarithm problem. The secure key size is generally > 1024 bits. Today even 2048 bits long key…

  • Encryption and Decryption

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    misamaliraza94
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    The generation of an ElGamal key pair is comparatively simpler than the equivalent process for RSA. But the encryption and decryption are slightly more complex than RSA. ElGamal Encryption Suppose sender wishes to send a plaintext to someone whose ElGamal public key is (p, g, y), then − C1 = gk mod p C2 =…