Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 33 for “"Hash functions"”.
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Design and analysis of hash functions
… fixed small size ‘message digest’ is known as a hash function. For the last two decades, many types of hash functions have been defined but, the most widely used in many of the cryptographic applications currently are hash functions based on block ciphers and the dedicated hash functions. Almost …
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Generic attacks on iterated hash functions
We survery the existing generic attacks on hash functions based on the MerkleÂDamgard construction: that is, attacks in which the compression function is treated as a black box.
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Security proofs for the MD6 hash function mode of operation
… cryptanalytic attacks on several commonly-used hash functions, such as MD4, MD5, SHA-0, and SHA1 [13, 38]. These culminated with the celebrated work of Wang, Yin, and Yu from 2005, which demonstrated relatively efficient methods for finding collisions in the SHA-1 hash function [37]. Although …
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Physical one-way functions
Modern cryptography relies on algorithmic one-way functions - numerical functions which are easy to compute but very difficult to invert. This dissertation introduces physical one-way firnctions and physical one-way hash functions as primitives for physical analogs of cryptosystems. Physical …
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Analysis and Design Security Primitives Based on Chaotic Systems for eCommerce
… which is built based on the security of hash functions, encryption algorithms and pseudorandom number generators. Chaotic systems and security algorithms have similar properties including sensitivity to any change or changes in the initial parameters, unpredictability, deterministic …
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Efficient data structures for information retrieval
… the application of efficient data structures and hashing algorithms to the problems of textual information storage and retrieval. We have developed static and dynamic techniques for handling large dictionaries, inverted lists, and optimizations applied to ranking algorithms. We have carried out an …
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Millimeter wave communications : from point-to-point links to agile network connections
… the space. Instead of scanning, Agile-link hashes the beam directions using a few carefully chosen hash functions. It then identifies the correct alignment by tracking how the energy changes across different hash functions. Two major limitations are addressed in this research. First is the …
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Combined robust and fragile watermarking algorithms for still images. Design and evaluation of combined blind discrete wavelet transform-based robust watermarking algorithms for copyright protection using mobile phone numbers and fragile watermarking algorithms for content authentication of digital still images using hash functions.
… using a fragile watermarking algorithm by using hash function (MD5) as watermarking information embedded in the spatial domain. The new algorithm showed high sensitivity against any tampering on the watermarked images. The combined fragile and robust watermarking caused minimal distortion to the …
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Maintaining secrecy when information leakage is unavoidable
… encryption schemes with very short keys, and (b) hash functions that leak no information about their input, yet-paradoxically-allow testing if a candidate vector is close to the input. One of the technical contributions of this research is to provide new, cryptographic uses of mathematical tools …
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Transmissions of Hashed Personally Identifiable Information to Third Parties Across Websites
… information with third-party trackers in hashed form, often claiming that hash functions provide privacy protection. Previous literature has shown this to be false by successfully re-identifying hashes of common personally identifiable information (PII). Despite this, websites continue to …
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Cryptographic coprocessors for embedded systems
… based digital signature algorithm is developed. Hash functions are also an important component of a cryptographic system. The FPGA implementation of recent hash function designs from the SHA-3 competition are discussed and a fair comparison methodology for hash functions presented. Many …
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Semi-Supervised Learning for Scalable and Robust Visual Search
… graph-based semi-supervised learning and hashing techniques. The graph-based approaches are used to improve accuracy, while hashing approaches are used to improve efficiency and cope with large-scale applications. A common theme shared between these two subareas of our work is the focus on …
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One Time Password Scheme Via Secret Sharing Techniques
… complexity of breaking encryption or hash functions for security. This thesis will present an efficient and information-theoretically secure one-time password system called Shamir-OTP that is based upon secret sharing techniques.
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Learning compact hashing codes for large-scale similarity search
… objects should have similar representations. Hashing algorithms, which encode objects into compact binary codes to preserve similarity, have demonstrated promising results in addressing these challenges. This dissertation studies the problem of learning compact hashing codes for large-scale …
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Towards Cycle-Level Verification of Constant-Time Cryptography
Cryptographic primitives–hash functions, symmetric key encryption algorithms, asymmetric key exchange algorithms, and more–are used everywhere to achieve security in modern computing. Since these algorithms have complicated, math-heavy implementations, they are typically used through cryptographic …
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Relationships between functionality, security, and privacy for multiparty computation, hashing, and encryption
… multiparty computation, collision-resistant hash functions, public key cryptography, and much more. This thesis explores three facets of this balance. First, we delve into Topology-Hiding Computation, which is multiparty computation where we also hide the communication network, strengthening …
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Binární znaménkové reprezentace celých čísel v kryptoanalýze hashovacích funkcí
… Representations of Integers in Cryptanalysis of Hash Functions Author: Jiří Vábek Department: Department of Algebra Supervisor: doc. RNDr. Jiří Tůma, DrSc., Department of Algebra Abstract: The work summarizes two main papers, A New Type of 2-block Colli- sions in MD5 and On the Number of Binary …
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Towards constant bandwidth overhead integrity checking of untrusted data
We present a trace-hash scheme and an adaptive tree-trace scheme to improve the performance of checking the integrity of arbitrarily-large untrusted data, when using only a small fixed-sized trusted state. Currently, hash trees are used to check the data. In many systems that use hash trees, …
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Key-Based Authentication Scheme for eVTOL Drones Using Chebyshev Chaotic Maps
… utilizes Chebyshev polynomials as chaotic maps, hash functions, and the AES-256 encryption technique. The network members can securely generate all encryption keys without sharing secret data, which solves one of the main problems of the symmetric encryption scheme in the authentication service. …
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Hardware Evaluation of SHA-3 Candidates
Cryptographic hash functions are used extensively in information security, most notably in digital authentication and data integrity verification. Their performance is an important factor of the overall performance of a secure system. In 2005, some groups of cryptanalysts were making increasingly …
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