Results 91 to 100 of about 2,222 (156)
On Lipschitz ball noncollapsing functions and uniform co-Lipschitz mappings of the plane
Abstract and Applied Analysis, 2005 We give a sharp estimate on the cardinality of point preimages of a uniform co-Lipschitz mapping on the plane. We also give a necessary and sufficient condition for a ball noncollapsing Lipschitz function to have a point with infinite preimage.
Olga Maleva
doaj +1 more source
Preimages Under the Stack-Sorting Algorithm [PDF]
Graphs and Combinatorics, 2016 We use a method for determining the number of preimages of any permutation under the stack-sorting map in order to obtain recursive upper bounds for the numbers $W_t(n)$ and $W_t(n,k)$ of $t$-stack sortable permutations of length $n$ and $t$-stack sortable permutations of length $n$ with exactly $k$ descents.
openaire +2 more sources
, 2013 Biometric recognition is more and more employed in authentication and access control of various applications. Biometric data are strongly linked with the user and do not allow revocability nor diversity, without an adapted post-processing. Cancelable biometrics, including the very popular algorithm BioHashing, is used to cope with the underlying ...
Lacharme, Patrick +2 more
openaire +2 more sources
Practical Preimage Attack on 5-Round Keccak[r=640, c=160]
IACR Transactions on Symmetric CryptologyInternal differential cryptanalysis has recently yielded a series of new results in the preimage cryptanalysis of round-reduced Keccak. While these existing attacks share a similar high-level framework, they differ in their technical details. This paper
Xiaoen Lin +6 more
doaj +1 more source
Novel hierarchical identity-based encryption scheme from lattice
Tongxin xuebao, 2017 Aiming at the high complexity in user’s private key extraction and large expansion ratio of trapdoor size in previous hierarchical identity-based encryption (HIBE) schemes,a new HIBE scheme was proposed.The implicit extension method to improve preimage ...
Qing YE +4 more
doaj +2 more sources
Tag Second-preimage Attack against π-cipher [PDF]
, 2014 The π-cipher is one of the candidates of the CAESAR competition. One of the advertised features of the π-cipher is tag second-preimage resistance: it should be hard to generate a message with a given tag, even for the legitimate key holder (insider ...
Leurent, Gaëtan
core +1 more source
The Symbiosis between Collision and Preimage Resistance [PDF]
, 2011 We revisit the definitions of preimage resistance, focussing on the question of finding a definition that is simple enough to prove security against, yet flexible enough to be of use for most applications.
Stam, Martijn +3 more
core +1 more source
Novel identity-based fully homomorphic encryption scheme from lattice
Tongxin xuebao, 2017 The previous identity-based homomorphic encryption schemes from lattice was analyzed.That the high complexity in previous schemes was mainly caused by trapdoor generation and preimage sampling was pointed out.A new solution was proposed.A novel identity ...
Yong-li TANG +4 more
doaj +2 more sources
Rimcompactness and Similar Properties in Preimages
Rocky Mountain Journal of Mathematics, 1992 The following is proved. Theorem 1: Suppose \(f: X\to Y\) is rimcompact and, for \(y\in Y\), \(f^{-1}(y)\) is rimcompact and has 0-dimensional boundary in \(X\). If \(Y\) is rimcompact then \(X\) is rimcompact. --- Theorem 2: Suppose \(f: X\to Y\) is rimperfect and, for \(y\in Y\), \(f^{-1}(y)\) is a TDI space (i.e.
openaire +3 more sources
Computational Complexity of Some Problems on Generalized Cellular Automations
Безопасность информационных технологий, 2012 We prove that the preimage problem of a generalized cellular automation is NP-hard. The results of this work are important for supporting the security of the ciphers based on the cellular automations.
P. G. Klyucharev
doaj