scholarly journals Applications of single-qubit rotations in quantum public-key cryptography

2008 ◽  
Vol 77 (3) ◽  
Author(s):  
Georgios M. Nikolopoulos
Keyword(s):  
Public Key Cryptography ◽  
Public Key ◽  
Single Qubit ◽  
Quantum Public Key

Securing M2M With Post-Quantum Public-Key Cryptography

2013 ◽  
Vol 3 (1) ◽  
pp. 106-116 ◽  
Author(s):  
Jie-Ren Shih ◽  
Yongbo Hu ◽  
Ming-Chun Hsiao ◽  
Ming-Shing Chen ◽  
Wen-Chung Shen ◽  
...  
Keyword(s):  
Public Key Cryptography ◽  
Public Key ◽  
Quantum Public Key

scholarly journals Optimizing the Decoding Process of a Post-Quantum Cryptographic Algorithm

2017 ◽  
Author(s):  
Antonio Guimarães ◽  
Diego F. Aranha ◽  
Edson Borin
Keyword(s):  
State Of The Art ◽  
Public Key Cryptography ◽  
Public Key ◽  
Constant Time ◽  
Side Channel ◽  
Security Level ◽  
Encryption Scheme ◽  
Cryptographic Algorithm ◽  
Overall Performance ◽  
Quantum Public Key

QcBits is a state-of-the-art constant-time implementation of a code-based encryption scheme for post-quantum public key cryptography. This paper presents an optimized version of its decoding process, which is used for message decryption. Our implementation leverages SSE and AVX instructions extensions and performs 3.6 to 4.8 times faster than the original version, while preserving the 80-bit security level and constant time execution. We also provide experimental data that indicates a further 1.4-factor speedup supposing the existence of instructions for vectorial conditional moves and 256-bit register shifts. Finally, we implemented countermeasures for side-channel security and showed that they do not affect the overall performance.

scholarly journals Universal quantum computation in a hidden basis

2010 ◽  
Vol 10 (7&8) ◽  
pp. 541-561
Author(s):  
L.M. Ioannou ◽  
M. Mosca
Keyword(s):  
Quantum Computation ◽  
Quantum Algorithm ◽  
Public Key Cryptography ◽  
Invariant Operator ◽  
Public Key ◽  
Natural Class ◽  
Relative Phase Shift ◽  
Efficient Approximation Algorithm ◽  
To Come ◽  
Quantum Public Key

Let $\ketz$ and $\keto$ be two states that are promised to come from known subsets of orthogonal subspaces, but are otherwise unknown. Our paper probes the question of what can be achieved with respect to the basis $\{\ketz,\keto\}^{\otimes n}$ of $n$ logical qubits, given only a few copies of the unknown states $\ketz$ and $\keto$. A phase-invariant operator is one that is unchanged under the relative phase-shift $\keto \mapsto e^{i \theta}\keto$, for any $\theta$, of all of the $n$ qubits. We show that phase-invariant unitary operators can be implemented exactly with no copies and that phase-invariant states can be prepared exactly with at most $n$ copies each of $\ket{\0}$ and $\ket{\1}$; we give an explicit algorithm for state preparation that is efficient for some classes of states (e.g. symmetric states). We conjecture that certain non-phase-invariant operations are impossible to perform accurately without many copies. Motivated by optical implementations of quantum computers, we define ``quantum computation in a hidden basis'' to mean executing a quantum algorithm with respect to the phase-shifted hidden basis $\{\ketz, e^{i\theta}\keto\}$, for some potentially unknown $\theta$; we give an efficient approximation algorithm for this task, for which we introduce an analogue of a coherent state of light, which serves as a bounded quantum phase reference frame encoding $\theta$. Our motivation was quantum-public-key cryptography, however the techniques are general. We apply our results to quantum-public-key authentication protocols, by showing that a natural class of digital signature schemes for classical messages is insecure. We also give a protocol for identification that uses many of the ideas discussed and whose security relates to our conjecture (but we do not know if it is secure).

Analisis dan Implementasi Protokol Otentikasi FIDO U2F

2017 ◽  
Vol 9 (1) ◽  
pp. 30-35
Author(s):  
Sunderi Pranata ◽  
Hargyo Tri Nugroho ◽  
Hirofumi Yamaki
Keyword(s):  
Public Key Cryptography ◽  
Authentication Protocol ◽  
Public Key ◽  
Next Generation ◽  
Index Terms ◽  
Mitm Attack

It is known that password itself is not enough for formidable authentication method since it has a lot of vulnerabilities. Multi factor authentication (MFA) is introduced for the next generation for good authentication to address that issue. MFA combines two or more of three principles of good security, “something you know”, “something you have”, and “something you are”. Most MFA mechanisms work as one time passwords (OTP). However, they can still be vulnerable to phishing and MiTM attack. On top of that, OTP can be hard to use as it requires user to input another password given by the device (SMS, token, authenticator). Implemented in small USB U2F device, FIDO U2F delivers easier yet stronger security on authentication process which implements public key cryptography, challenge-response protocol, and phishing and MitM protection.  Index Terms— Authentication protocol, FIDO U2F, Multi factor authentication, OTP

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