Feature hashing

About: Feature hashing is a research topic. Over the lifetime, 993 publications have been published within this topic receiving 51462 citations.

A Novel Data Mining Approach for Detecting Spam Emails using Robust Chi-Square Features

Abstract: In spam filtering techniques, the classification of emails are performed on the basis of a collection words that are extracted from the training set. The accuracy and performance of the classifier highly depends on features and length of feature space. Feature selection methods are used in such scenario for evaluating the best features for classification. In an attempt to develop strong spam filtering model we rank the features using Chi--Square feature ranking method and also investigate the effectiveness of feature length on classification accuracy. The results are promising and also the feature ranking method proposed is effective than other methods referred in the literature.

Locality preserving hashing for fast image search: theory and applications

Abstract: State-of-the-art hashing methods, such as the kernelised locality-sensitive hashing and spectral hashing, have high algorithmic complexities to build the hash codes and tables. Our observation from...

Lossy Projective Hashing and Its Applications

Abstract: In this paper, we introduce a primitive called lossy projective hashing. It is unknown before whether smooth projective hashing Cramer-Shoup, Eurocrypt'02 can be constructed from dual projective hashing Wee, Eurocrypt'12. The lossy projective hashing builds a bridge between dual projective hashing and smooth projective hashing. We give instantiations of lossy projective hashing from DDH, DCR, QR and general subgroup membership assumptions including $$2^k$$2k-th residue, p-subgroup and higher residue assumptions. We also show how to construct lossy encryption and fully IND secure deterministic public key encryption from lossy projective hashing. We give a construction of lossy projective hashing via dual projective hashing. We prove that lossy projective hashing can be converted to smooth projective hashing via pairwise independent hash functions, which in turn yields smooth projective hashing from dual projective hashing.We propose a direct construction of lossy encryption via lossy projective hashing. Our construction is different from that given by Hemenway et al. Eurocrypt 2011 via smooth projective hashing. In addition, we give a fully IND secure deterministic public key encryption via lossy projective hashing and one round UCE secure hash functions recently introduced by Bellare et al. Crypto 2013.

Hash + list Based on the Index of Special-Memory Database System Design and Implementation

Abstract: This paper study memory database management system of the principles and key technologies,Monitoring system based on mobile messaging features in memory database,Designed and implemented based on the indices of a special Hash + type memory database system,Analysis system used to solve the spam messages in the massive access problems.

Using Improved Fibonacci Hash Transform to Increase the Robustness of Meaningful Watermarking Algorithm

Abstract: In order to enhance the security of hashing algorithm,the authors propose a generalized two dimensional matrix hashing algorithm.The algorithm has several optional matrices, and the image can be restored through reverse transform. Thus, it is very difficult to decode the hashing algorithm; the security is enhanced via using the selected matrix and iteration time as the secret keys.Numerical experiments show that, under various image processing and attacks, the proposed algorithm has such advantages as good robustness, high security,requiring not the original image for watermarking extraction, etc.