This paper discusses the problems of the MPEG video encryption algorithm by using random permutation list instead of zigzag order within the MPEG compression process. We show that 1) the en-cryption method causes a signiicant size increase of the MPEG video stream, hence defeats the purpose of compression, and 2) the encryption method can not withstand the known-plaintext attack, therefore, sho...

Prefix-preserving encryption (PPE) is an important type of encryption scheme, having a wide range of applications, such as IP addresses anonymization, prefix-matching search, and rang search. There are two issues in PPE schemes, security proof and single key requirement. Existing security proofs for PPE only reduce the security of a real PPE scheme to that of the ideal PPE object by showing the...

Cloud Computing, the long term goal of utility computing has transformed the IT industry a lot. Data constantly contain sensitive information should be secured by policies and regulation defined by various organizations. However, information on cloud always causes privacy problems. Data encryption protects privacy and confidentiality but efficiency is not ensured. Symmetric Searchable Encryptio...

let $g$ be a finite simple graph whose vertices and edges are weighted by two functions. in this paper we shall define and calculate entropy of a dynamical system on weights of the graph $g$, by using the weights of vertices and edges of $g$. we examine the conditions under which entropy of the dynamical system is zero, possitive or $+infty$. at the end it is shown that, for $rin [0,+infty]$, t...

Property preserving encryption (PPE) can enable database systems to process queries over encrypted data. While a lot of research in this area focusses on doing so with SQL databases, NoSQL (Not only SQL) cloud databases are good candidates either. On the one hand, they usually provide enough space to store the typically larger ciphertexts and special indexes of PPE-schemes. On the other hand in...

Format-preserving encryption (FPE) encrypts a plaintext of some specified format into a ciphertext of the same format—for example, encrypting a social-security number into a social-security number. In this survey we describe FPE and review known techniques for achieving it. These include FFX, a recent proposal made to NIST.

Homomorphic encryption enables computations on encrypted data. This property makes such encryption schemes useful in a wide variety of privacy preserving applications. This paper provides a brief survey on the homomorphic encryption. We describe the homomorphic cryptosystems from partially homomorphic encryption to fully homomorphic encryption. We also give some security analysis and describe h...

A privacy-preserving biometric matching technique for binary vectors more efficient than the Goldwasser-Micali approach has been proposed in “Customisation of Paillier Homomorphic Encryption for Efficient Binary Biometric Feature Vector Matching [PPRU14]” based on exploiting Paillier’s capability of encrypting messages larger than one bit at a time. We demonstrate that the suggested solution do...

Datatype­Preserving Encryption (DTP) enables encryption of values within a certain character set into ciphertext restricted to the same set, while still keeping data length. This is in contrast to conventional block cipher modes which produce binary data, i e each encrypted character may have an arbitrary value, possibly outside the original character set, often accompanied with a length expans...