1] Using simultaneous measurements of the upstream solar wind and of energetic electrons at geosynchronous orbit, we analyze the response of electrons over a wide energy range, 50 keV to 6 MeV, to solar wind variations. Enhancements of energetic electron fluxes over this whole energy range are modulated by the solar wind speed and the polarity of the interplanetary magnetic field (IMF). The solar wind speed seems to be a dominant controlling parameter for electrons of all energy. Electron enhancements occur after solar wind speed enhancements with a time delay that increases with energy and that also depends on the average polarity of the IMF. The electron enhancements have a shorter delay if the IMF B z < 0 and a longer delay if the IMF B z > 0 during the solar wind speed enhancement. The dependence on solar wind condition varies for different energy electrons, with lower-energy electrons (<200 keV) responding more to the polarity of the IMF and higher energy electrons (>1 MeV) responding more to the solar wind speed. The variations of different energy electrons are well correlated among themselves. For five years, 1995--1999, the correlation coefficients of 1.1--1.5 MeV electrons with lower-energy electrons, 50--75, 105--150, 225--315, and 500--750 keV, are 0.55, 0.64, 0.74, and 0.90. This correlation is enhanced if a time shift proportional to their energy difference is included. The optimal time shifts and the corresponding correlation coefficients for the four lower energy electrons are 36, 32, 13, and 7 hours and 0.75, 0.77, 0.81, and 0.92, respectively.Citation: Li, X., D. N. Baker, M. Temerin, G. Reeves, R. Friedel, and C. Shen (2005), Energetic electrons, 50 keV to 6 MeV, at geosynchronous orbit: Their responses to solar wind variations, Space Weather, 3, S04001,

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The wide deployment of cloud-assisted electronic health (eHealth) systems has already shown great benefits in managing electronic health records (EHRs) for both medical institutions and patients. However, it also causes critical security concerns. Since once a medical institution generates and outsources the patients' EHRs to cloud servers, patients would not physically own their EHRs but the medical institution can access the EHRs as needed for diagnosing, it makes the EHRs integrity protection a formidable task, especially in the case that a medical malpractice occurs, where the medical institution may collude with the cloud server to tamper with the outsourced EHRs to hide the medical malpractice. Traditional cryptographic primitives for the purpose of data integrity protection cannot be directly adopted because they cannot ensure the security in the case of collusion between the cloud server and medical institution. In this paper, a secure cloud-assisted eHealth system is proposed to protect outsourced EHRs from illegal modification by using the blockchain technology (blockchain-based currencies, e.g., Ethereum). The key idea is that the EHRs only can be outsourced by authenticated participants and each operation on outsourcing EHRs is integrated into the public blockchain as a transaction. Since the blockchain-based currencies provide a tamper-proofing way to conduct transactions without a central authority, the EHRs cannot be modified after the corresponding transaction is recorded into the blockchain. Therefore, given outsourced EHRs, any participant can check their integrity by checking the corresponding transaction. Security analysis and performance evaluation demonstrate that the proposed system can provide a strong security guarantee with a high efficiency.

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