On the Security of TLS Resumption and Renegotiation

The Transport Layer Security(TLS) protocol is the most important standard on the Internet for key exchange. TLS standard supports many additional handshake modes such as resumption and renegotiation besides the full handshake. The interaction and dependence of different modes may lead to some practical attacks on TLS. In 2014, Bhargavan et al. described a triple handshake attack on TLS 1.2 by exploiting the sequential running of three different modes of TLS, which can lead to a client impersonation attack after the third handshake. Subsequently, TLS 1.2 was patched with the extended master secret extension of RFC 7627 to prevent this attack. In this paper we introduce a new definition of "uniqueness" and present a renegotiable & resumable ACCE security model. We identify the triple handshake attack within the new model, and furthermore show TLS with the proposed fix can be proven secure in our model.

Data security and privacy computing in artificial intelligence

Artificial intelligence(AI)is a field of computer science dedicated to creating systems and algorithms that can perform tasks typically requiring human intelligence,such as learning,problem-solving,language understanding,and decision-making,contributing to a wide array of applications across diverse industries.The development of AI,such as machine learning and deep learning,has revolutionized data processing and analysis.This transformation is rapidly changing human life and has allowed for many practical AI based applications,including biometric recognition,text/sentimental analysis,and attack detection in the fields of health care,finance,autonomous vehicles,personalized recommendations.However,the potential benefits of AI are hindered by issues,such as insecurity and privacy violations in data processing and communication.

创新发展中的可信计算理论与技术

可信计算以硬件安全机制为基础,建立可信赖计算环境,从体系结构上全面增强系统和网络信任,是当前学术界和产业界的关注热点.随着信息技术的深入发展,新应用场景的不断涌现,网络空间的安全威胁日益严峻,因此可信计算在重要信息系统的安全防护领域将发挥越来越重要的作用.本文从创新发展角度,围绕作者20年来在可信计算领域的研究成果,综述了可信计算理论的发展历程,提炼总结出涵盖两大方法基础、三大信任核心和四大关键技术的可信计算技术体系,阐述了移动可信计算、抗量子可信计算、可信物联网、可信云、可信区块链等方面的重要研究问题以及可信计算在这些领域的融合创新成果.在移动可信计算方面,软硬件结合的可信执行环境体系架构设计和实现是研究重点,其次,移动操作系统内核运行时安全隔离防护,以及基于可信执行环境(trusted execution environment,TEE)的移动应用安全防护也是两个重要研究问题.在可信物联网方面,由于嵌入式环境本身的特性以及资源的受限,轻量级的信任根构建、高效安全的软件证明、实用的安全代码更新机制、集群设备证明是该领域有待进一步研究的重要问题.在抗量子可信计算、可信云、可信区块链等新型场景中,可信计算技术也在不断地拓展其应用边界,发挥更加重要的作用.最后本文展望和讨论了可信计算未来的发展趋势.

The theory and practice in the evolution of trusted computing

Trusted computing(TC)is an emerging technology to enhance the security of various computing platforms by a dedicated secure chip(TPM/TCM),which is widely accepted by both the industrial and academic world.This paper attempts to sketch the evolution of TC from the view of our theoretical and engineering work.In theory,we focus on protocol design and security analysis.We have proposed the first ECDAA protocol scheme based on q-SDH assumption,which highlights a new way to design direct anonymous attestation scheme.In technical evolution,we discuss the key technologies of trust chain,trusted network connection and TC testing and evaluation.We break through several key technologies such as trusted boot,OS measurement and remote attestation,and implement a TC system from TPM/TCM to network.We also design and implement a testing and evaluation system of TC platform,which is the first one put into practical application in China.Finally,with the rapid development of cloud computing and mobile applications,TC is moving toward some new directions,such as the trust in cloud and mobile environments,new TPM standard,and flexible trust execution environment trust establishment method.

Formal analysis of TPM2.0 key management APIs

The trusted platform module(TPM),a system component implemented on physical resources,is designed to enable computers to achieve a higher level of security than the security level that it is possible to achieve by software alone.For this reason,the TPM provides a way to store cryptographic keys and other sensitive data in its memory,which is shielded from access by any entity other than the TPM.Users who want to use those keys and data to achieve some security goals are restricted to interact with the TPM through its APIs defined in the TPM specification.Therefore,whether the TPM can provide Protected Capabilities it claimed depends to a large extent on the security of its APIs.In this paper,we devise a formal model,which is accessible to a fully mechanized analysis,for the key management APIs in the TPM2.0 specification.We identify and formalize security properties of these APIs in our model and then successfully use the automated prover Tamarin to obtain the first mechanized analysis of them.The analysis shows that the key management subset of TPM APIs preserves the secrecy of non-duplicable keys for unbounded numbers of fresh keys and handles.The analysis also reports that the key duplication mechanism,used to duplicate a key between two hierarchies,is vulnerable to impersonation attacks,which enable an adversary to recover the duplicated key of the originating hierarchy or import his own key into the destination hierarchy.Aiming at avoiding these vulnerabilities,we proposean approach,which restricts the originating and destination TPMs to authenticate each other’s identity during duplication.Then we formally demonstrate that our approach maintains the secrecy of duplicable keys when they are duplicated.

ON THE NONEXISTENCE OF NONTRIVIAL SMALL CYCLES OF THE μ FUNCTION IN 3x+ 1 CONJECTURE

This paper studies the property of the recursive sequences in the 3x ＋ 1 conjecture. The authors introduce the concept of μ function, with which the 3x ＋ 1 conjecture can be transformed into two other conjectures： one is eventually periodic conjecture of the μ function and the other is periodic point conjecture. The authors prove that the 3x ＋ 1 conjecture is equivalent to the two conjectures above. In 2007, J. L. Simons proved the non-existence of nontrivial 2-cycle for the T function. In this paper, the authors prove that the μ function has nol-periodic points for 2 ≤ 1 ≤12. In 2005, J. L. Simons and B. M. M de Weger proved that there is no nontrivial/-cycle for the T function for 1 ≤68, and in this paper, the authors prove that there is no nontrivial l-cycle for the μ function for 2 ≤ 1≤ 102.

Concretely ecient secure multi-party computation protocols:survey and mor

Secure multi-party computation(MPC)allows a set of parties to jointly compute a function on their private inputs,and reveals nothing but the output of the function.In the last decade,MPC has rapidly moved from a purely theoretical study to an object of practical interest,with a growing interest in practical applications such as privacy-preserving machine learning(PPML).In this paper,we comprehensively survey existing work on concretely ecient MPC protocols with both semi-honest and malicious security,in both dishonest-majority and honest-majority settings.We focus on considering the notion of security with abort,meaning that corrupted parties could prevent honest parties from receiving output after they receive output.We present high-level ideas of the basic and key approaches for designing di erent styles of MPC protocols and the crucial building blocks of MPC.For MPC applications,we compare the known PPML protocols built on MPC,and describe the eciency of private inference and training for the state-of-the-art PPML protocols.Further-more,we summarize several challenges and open problems to break though the eciency of MPC protocols as well as some interesting future work that is worth being addressed.This survey aims to provide the recent development and key approaches of MPC to researchers,who are interested in knowing,improving,and applying concretely ecient MPC protocols.

Preface

在第二十一个世纪，网络和信息安全为到打战争的一种新生活方式和一条新途径正在成为电子空间的批评基础。从国家策略的观点，关于 Snowden 和国家安全机构棱柱的丑闻证明了所有联网因特网行为在在在信息技术(信息技术) 主导的那些国家边的全球世界上的监视下面的信息，通讯信息，和个人。在 2011， USA 为电子空间释放了国际策略[1 ] ，它在全球电子安全表达一个新趋势，与从防卫改变到冒犯的 US 电子安全策略。相应于这个趋势，在 USA 的军队网络战争营发射了巨大的砍的最近的年里，反对我们的公民的攻击和利用联网基础结构。他们试图严重损坏另外的国家造破坏电子武器边的批评基础结构并且……