Statistical attack against iris-biometric fuzzy commitment schemes

2011 ◽  
Author(s):  
Christian Rathgeb ◽  
Andreas Uhl
Keyword(s):  
Statistical Attack ◽  
Commitment Schemes

Keamanan file dokumen menggunakan algoritme Advanced Encryption Standard pada aplikasi berbasis Android

JNANALOKA ◽  
2020 ◽  
pp. 11-23
Author(s):  
Emy Setyaningsih
Keyword(s):  
Advanced Encryption Standard ◽  
Brute Force ◽  
Statistical Attack

Seiring dengan peningkatan kemampuan perangkat mobile terutama media penyimpanan yang ukurannya semakin besar, memungkinkan pengguna menyimpan file dokumen penting ke perangkat mobile. File dokumen rahasia tersebut menjadi sangat rentan untuk diketahui, diam- bil atau bahkan dimanipulasi dan disalahgunakan oleh pihak lain yang tidak berhak mengakses perangkat mobile tersebut. Oleh karena itu, dibutuhkan aplikasi berbasis Android yang dapat melindungi file dokumen agar tidak dapat dibaca oleh orang lain. Salah satu metode yang dapat digunakan untuk melindungi file dokumen tersebut dari serangan pihak yang tidak bertanggung jawab adalah metode kriptografi. Algoritme kriptografi yang paling sering digunakan untuk mengamankan dokumen dalam bentuk teks adalah algoritme Advanced Encryption Standard (AES). Penelitian ini berhasil membangun aplikasi pengamanan file dokumen dengan format pe- nyimpanan *.pdf, *.doc, *.ppt dan *.xls menggunakan algoritme AES berbasis Android. Aplikasi yang dibangun memiliki kelebihan pada penggunaan kunci AES yang selalu berbeda untuk pro- ses enkripsi, sehingga lebih aman terhadap serangan brute-force. Penelitian ini juga melakukan perbandingan kinerja dari AES-128, AES-192 dan AES-256 berdasarkan kecepatan proses enkri- psi dan dekripsi. Berdasarkan pengujian yang dilakukan, kecepatan waktu enkripsi dan dekripsi tidak dipengaruhi oleh jenis format penyimpanan file, namun dipengaruhi oleh ukuran file dan ukuran kuncinya. Semakin besar ukuran file asli (plainteks) maka semakin besar pula kebutuhan waktu prosesnya. Proses enkripsi dan dekripsi menggunakan panjang kunci 128 bit juga membu- tuhkan waktu paling cepat dibandingkan menggunakan panjang kunci 256 bit. Hasil pengujian menggunakan uji analisis histogram, memperlihatkan histogram dari cipherteks relatif rata yang menunjukkan algoritme kriptografi AES aman terhadap statistical attack. Hasil ini menunjukkan bahwa aplikasi berbasis Android untuk keamanan dokumen menggunakan algoritme AES yang dibangun memiliki keamanan cukup tinggi serta cepat proses enkripsi dan dekripsinya.

DL-Extractable UC-Commitment Schemes

2019 ◽  
pp. 385-405 ◽  
Author(s):  
Behzad Abdolmaleki ◽  
Karim Baghery ◽  
Helger Lipmaa ◽  
Janno Siim ◽  
Michał Zając
Keyword(s):  
Commitment Schemes

scholarly journals Efficient Non-malleable Commitment Schemes

2009 ◽  
Vol 22 (4) ◽  
Author(s):  
Marc Fischlin ◽  
Roger Fischlin
Keyword(s):  
Commitment Schemes

scholarly journals Efficient Non-Malleable Commitment Schemes

2009 ◽  
Vol 24 (1) ◽  
pp. 203-244 ◽  
Author(s):  
Marc Fischlin ◽  
Roger Fischlin
Keyword(s):  
Commitment Schemes

scholarly journals On the Computational Collapse of Quantum Information

2003 ◽  
Vol 10 (3) ◽  
Author(s):  
Claude Crépeau ◽  
Paul Dumais ◽  
Dominic Mayers ◽  
Louis Salvail
Keyword(s):  
Quantum Information ◽  
Quantum State ◽  
Weak Form ◽  
Black Box ◽  
Binding Property ◽  
Extra Information ◽  
Quantum Measure ◽  
Commitment Schemes ◽  
Weak Binding ◽  
Valid Proof

We analyze the situation where computationally binding string commitment schemes are used to force the receiver of a BB84 encoding of a classical bitstring to measure upon reception. Since measuring induces an irreversible collapse to the received quantum state, even given extra information after the measurement does not allow the receiver to evaluate reliably some predicates apply to the classical bits encoded in the state. This fundamental quantum primitive is called quantum measure commitment (QMC) and allows for secure two-party computation of classical functions. An adversary to QMC is one that can both provide valid proof of having measured the received states while still able to evaluate a predicate applied to the classical content of the encoding. We give the first quantum black-box reduction for the security of QMC to the binding property of the string commitment. We characterize a class of quantum adversaries against QMC that can be transformed into adversaries against a weak form for the binding property of the string commitment. Our result provides a construction for 1--2-oblivious transfer that is computationally secure against the receiver and unconditionally secure against the sender from any string commitment scheme satisfying a weak binding property.

scholarly journals An Approach to the Construction of a Recursive Argument of Polynomial Evaluation in the Discrete Log Setting

Electronics ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 131
Author(s):  
Sungwook Kim
Keyword(s):  
Class Group ◽  
Building Blocks ◽  
Security Requirements ◽  
Ideal Class ◽  
Ideal Class Group ◽  
Imaginary Quadratic Fields ◽  
Polynomial Evaluation ◽  
Commitment Scheme ◽  
Commitment Schemes ◽  
Cryptographic Assumptions

Succinct Non-interactive Arguments of Knowledge (SNARks) are receiving a lot of attention as a core privacy-enhancing technology for blockchain applications. Polynomial commitment schemes are important building blocks for the construction of SNARks. Polynomial commitment schemes enable the prover to commit to a secret polynomial of the prover and convince the verifier that the evaluation of the committed polynomial is correct at a public point later. Bünz et al. recently presented a novel polynomial commitment scheme with no trusted setup in Eurocrypt’20. To provide a transparent setup, their scheme is built over an ideal class group of imaginary quadratic fields (or briefly, class group). However, cryptographic assumptions on a class group are relatively new and have, thus far, not been well-analyzed. In this paper, we study an approach to transpose Bünz et al.’s techniques in the discrete log setting because the discrete log setting brings a significant improvement in efficiency and security compared to class groups. We show that the transposition to the discrete log setting can be obtained by employing a proof system for the equality of discrete logarithms over multiple bases. Theoretical analysis shows that the transposition preserves security requirements for a polynomial commitment scheme.

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