A Fair E-Cash Scheme Based on Elliptic Curve Cryptography

A new fair off-line electronic cash scheme on elliptic curve cryptography was presented. The new scheme is more efficient than those by extending fair off-line electronic cash scheme from finite field into elliptic curve cryptography and introducing a new elliptic curve discrete logarithm assumption. The expiry date and denomination are embedded into the blindly signed coin by integrating partially blind signature with restrictive blind signature. A bank need not use different public keys for different coin values, shops and users need not carry a list of bank’s public keys to verify in their electronic wallet. At the same time, the bank just needs to keep undue electronic coins for double spending check in his database, thus bank’s database can be dramatically reduced.

An Efficient Fair Electronic Cash System

In this paper, an efficient fair e-cash system is presented. Based on the improved Brands’ e-cash scheme, it is expanded by adding two roles, government and judges. The user can keep unconditionally anonymous in normal transactions. Authorized by the judges, the government can remove the identity of an illegal user with the help of the bank. So such misuse as blackmailing or money laundering can be prevented. Therefore, this scheme is more efficient, more suitable for adopting pre-processing and post-processing and more practical. In the paper, the details of the scheme are described, its security is proved, and its efficiency is analyzed.

Anonymity control in electronic check systems

Electronic check systems, as one of electronic payment systems, are more desirable than other electronic cash systems. In the system, only a single cheek is used to pay any price that is not more than the face value. The main problem in check systems is to design an efficient refund mechanism that makes refired cheeks undistinguished from initial checks during payment and deposit. The problem of anonymity control also called fairmess is also an important issue in check systelns. All check systems yet are unconditional anonymity that opens the door to misuse for crime such as laundering and blackmailing. In this paper, the notion of anonylnity revocation is introduced to electronic check system for the fitst thne, and a model of fair electronic check system is proposed. An effieient fair online electronic check system with reusable refund is presented. In the system, a passive trustee is elnployed to revoke the anonymity of unhonest users. Moreover, the system solves the reusability problem of refunds thanks to the RSA-based partially signature. The system is efficient and meets all basic security requirements.

Andreev Reflection of Pseudo-Correlated Pairs Electrons in the System ＂Superconductor-Fluctuation Superconductor-Superconductor＂

In the article, the Josephson system ＂Superconductor-Fluctuation Superconductor-Superconductor＂, consisting of a combination of superconductors with a fluctuation superconductor was considered. The possibility of transformation of the superconducting （Cooper） pairs in psevdocorrelated （fluctuation） of a pair of electrons is shown, and vice versa, the fluctuation pairs in the Cooper pairs in such a Josephson system. The characteristic features of the Andreev reflection of the weakly bound electron, which is part of the fluctuation pairs in the interface ＂fluctuation superconductor-superconductor＂ with a probability of forming a pair of ＂Electron-Hole＂ and the generation of psevdocorrelated pair discussed. The probability of formation of two correlated superconducting electron pairs, forming original cluster with a charge 4e, in the interface ＂Fluctuation Superconductor-Superconductor＂ as a result of transmutation of the reflected hole into an electron or subjection Andreev reflection of both electrons of fluctuation pairs is viewed. The above processes may be useful for better understanding the fluctuation effects in superconducting materials which appear at temperatures above the critical value.

Some properties of field-aligned electron events in high-altitude polar regions

Using data from the Cluster spacecraft from January 2003 to December 2004, we perform a statistical study on some properties of the field-aligned electron(FAE) events and interplanetary magnetic field(IMF) By dependence of FAE events with different durations in high-altitude polar regions. A total of 1335 FAE events were observed by the C3 spacecraft. More down-flowing events were observed in the Southern Hemisphere, and more up-flowing events were observed in the Northern Hemisphere. It proves that down-flowing events mainly originate from magnetosphere or solar wind and up-flowing events are mainly derived from ionosphere. Short-lifetime events showed a morning concentration in the magnetic local time distribution, and long-lifetime events were concentrated both before and after noon. For the IMF By dependence of the FAE events, short-lifetime events were much affected by IMF By and resulted in a morning concentration, while the long-lifetime events were almost unaffected by IMF By. With further analysis, we determined that the short-lifetime and long-lifetime events had different sources.