1,072 research outputs found
EASYFLOW: Keep Ethereum Away From Overflow
While Ethereum smart contracts enabled a wide range of blockchain
applications, they are extremely vulnerable to different forms of security
attacks. Due to the fact that transactions to smart contracts commonly involve
cryptocurrency transfer, any successful attacks can lead to money loss or even
financial disorder. In this paper, we focus on the overflow attacks in Ethereum
, mainly because they widely rooted in many smart contracts and comparatively
easy to exploit. We have developed EASYFLOW , an overflow detector at Ethereum
Virtual Machine level. The key insight behind EASYFLOW is a taint analysis
based tracking technique to analyze the propagation of involved taints.
Specifically, EASYFLOW can not only divide smart contracts into safe contracts,
manifested overflows, well-protected overflows and potential overflows, but
also automatically generate transactions to trigger potential overflows. In our
preliminary evaluation, EASYFLOW managed to find potentially vulnerable
Ethereum contracts with little runtime overhead.Comment: Proceedings of the 41st International Conference on Software
Engineering: Companion Proceedings. IEEE Press, 201
Safety of Mesenchymal Stem Cells for Clinical Application
Mesenchymal stem cells (MSCs) hold great promise as therapeutic agents in regenerative medicine and autoimmune diseases, based on their differentiation abilities and immunosuppressive properties. However, the therapeutic applications raise a series of questions about the safety of culture-expanded MSCs for human use. This paper summarized recent findings about safety issues of MSCs, in particular their genetic stability in long-term in vitro expansion, their cryopreservation, banking, and the role of serum in the preparation of MSCs
Interference bands in decays of doubly-charged Higgs bosons to dileptons in the minimal type-II seesaw model at the TeV scale
The dileptonic decays of doubly-charged Higgs bosons H^{\pm\pm} are
investigated in the minimal type-II seesaw model with one Higgs triplet \Delta
and one heavy Majorana neutrino N_1 at the TeV scale. We show that the
branching ratios {\cal B}(H^{\pm\pm} \to l^\pm_\alpha l^\pm_\beta) depend not
only on the mass and mixing parameters of three light neutrinos \nu_i (for
i=1,2,3), but also on those of N_1. Assuming the mass of N_1 to lie in the
range 200 GeV--1 TeV, we figure out the generous interference bands for the
contributions of \nu_i and N_1 to {\cal B}(H^{\pm\pm} \to l^\pm_\alpha
l^\pm_\beta): \sqrt{|\sin\theta_{i4} \sin\theta_{j4}|} \sim 10^{-8}--10^{-5},
where \theta_{i4} and \theta_{j4} measure the strength of charged-current
interactions of N_1. We illustrate some salient features of the interference
bands by considering three typical mass patterns of \nu_i, and stress that it
is very difficult to distinguish the type-II seesaw model from the triplet
seesaw model in such a parameter region at the Large Hadron Collider.Comment: RevTex 14 pages, 3 figures, more discussions added, accepted for
publication in Phys. Lett.
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