Keeping Authorities "Honest or Bust" with Decentralized Witness Cosigning

The secret keys of critical network authorities - such as time, name, certificate, and software update services - represent high-value targets for hackers, criminals, and spy agencies wishing to use these keys secretly to compromise other hosts. To protect authorities and their clients proactively from undetected exploits and misuse, we introduce CoSi, a scalable witness cosigning protocol ensuring that every authoritative statement is validated and publicly logged by a diverse group of witnesses before any client will accept it. A statement S collectively signed by W witnesses assures clients that S has been seen, and not immediately found erroneous, by those W observers. Even if S is compromised in a fashion not readily detectable by the witnesses, CoSi still guarantees S's exposure to public scrutiny, forcing secrecy-minded attackers to risk that the compromise will soon be detected by one of the W witnesses. Because clients can verify collective signatures efficiently without communication, CoSi protects clients' privacy, and offers the first transparency mechanism effective against persistent man-in-the-middle attackers who control a victim's Internet access, the authority's secret key, and several witnesses' secret keys. CoSi builds on existing cryptographic multisignature methods, scaling them to support thousands of witnesses via signature aggregation over efficient communication trees. A working prototype demonstrates CoSi in the context of timestamping and logging authorities, enabling groups of over 8,000 distributed witnesses to cosign authoritative statements in under two seconds.Comment: 20 pages, 7 figure

An Internet-Wide Analysis of Diffie-Hellman Key Exchange and X.509 Certificates in TLS

Transport Layer Security (TLS) is a mature cryptographic protocol, but has flexibility during implementation which can introduce exploitable flaws. New vulnerabilities are routinely discovered that affect the security of TLS implementations. We discovered that discrete logarithm implementations have poor parameter validation, and we mathematically constructed a deniable backdoor to exploit this flaw in the finite field Diffie-Hellman key exchange. We described attack vectors an attacker could use to position this backdoor, and outlined a man-in-the-middle attack that exploits the backdoor to force Diffie-Hellman use during the TLS connection. We conducted an Internet-wide survey of ephemeral finite field Diffie-Hellman (DHE) across TLS and STARTTLS, finding hundreds of potentially backdoored DHE parameters and partially recovering the private DHE key in some cases. Disclosures were made to companies using these parameters, resulting in a public security advisory and discussions with the CTO of a billion-dollar company. We conducted a second Internet-wide survey investigating X.509 certificate name mismatch errors, finding approximately 70 million websites invalidated by these errors and additionally discovering over 1000 websites made inaccessible due to a combination of forced HTTPS and mismatch errors. We determined that name mismatch errors occur largely due to certificate mismanagement by web hosting and content delivery network companies. Further research into TLS implementations is necessary to encourage the use of more secure parameters

A survey on security issues and solutions at different layers of Cloud computing

Cloud computing offers scalable on-demand services to consumers with greater flexibility and lesser infrastructure investment. Since Cloud services are delivered using classical network protocols and formats over the Internet, implicit vulnerabilities existing in these protocols as well as threats introduced by newer architectures raise many security and privacy concerns. In this paper, we survey the factors affecting Cloud computing adoption, vulnerabilities and attacks, and identify relevant solution directives to strengthen security and privacy in the Cloud environment

Enhance Linux Security Server Misconfigurations and hardening Methods

The calamity begins if an attacker successfully compromises a system and gains access to high-level privileges. This paper presents and addresses a vulnerable Linux server with typical flaws and configuration errors. This paper aims to show how these widespread vulnerabilities might be used by an attacker to compromise the server. In order to prevent building and setting up a Linux server with risks and low security, as well as to guarantee the integrity and confidentiality of user and customer information, this paper instructs aspiring system administrators and developers on how to avoid making such errors in their initial configuration for this servers set of examples

A Distributed Trust Framework for Privacy-Preserving Machine Learning

When training a machine learning model, it is standard procedure for the researcher to have full knowledge of both the data and model. However, this engenders a lack of trust between data owners and data scientists. Data owners are justifiably reluctant to relinquish control of private information to third parties. Privacy-preserving techniques distribute computation in order to ensure that data remains in the control of the owner while learning takes place. However, architectures distributed amongst multiple agents introduce an entirely new set of security and trust complications. These include data poisoning and model theft. This paper outlines a distributed infrastructure which is used to facilitate peer-to-peer trust between distributed agents; collaboratively performing a privacy-preserving workflow. Our outlined prototype sets industry gatekeepers and governance bodies as credential issuers. Before participating in the distributed learning workflow, malicious actors must first negotiate valid credentials. We detail a proof of concept using Hyperledger Aries, Decentralised Identifiers (DIDs) and Verifiable Credentials (VCs) to establish a distributed trust architecture during a privacy-preserving machine learning experiment. Specifically, we utilise secure and authenticated DID communication channels in order to facilitate a federated learning workflow related to mental health care data.Comment: To be published in the proceedings of the 17th International Conference on Trust, Privacy and Security in Digital Business - TrustBus202

SecureQEMU: Emulation-based Software Protection Providing Encrypted Code Execution and Page Granularity Code Signing

This research presents an original emulation-based software protection scheme providing protection from reverse code engineering (RCE) and software exploitation using encrypted code execution and page-granularity code signing, respectively. Protection mechanisms execute in trusted emulators while remaining out-of-band of untrusted systems being emulated. This protection scheme is called SecureQEMU and is based on a modified version of Quick Emulator (QEMU) [5]. RCE is a process that uncovers the internal workings of a program. It is used during vulnerability and intellectual property (IP) discovery. To protect from RCE program code may have anti-disassembly, anti-debugging, and obfuscation techniques incorporated. These techniques slow the process of RCE, however, once defeated protected code is still comprehensible. Encryption provides static code protection, but encrypted code must be decrypted before execution. SecureQEMUs\u27 scheme overcomes this limitation by keeping code encrypted during execution. Software exploitation is a process that leverages design and implementation errors to cause unintended behavior which may result in security policy violations. Traditional exploitation protection mechanisms provide a blacklist approach to software protection. Specially crafted exploit payloads bypass these protection mechanisms. SecureQEMU provides a whitelist approach to software protection by executing signed code exclusively. Unsigned malicious code (exploits, backdoors, rootkits, etc.) remain unexecuted, therefore, protecting the system. SecureQEMUs\u27 cache mechanisms increase performance by 0.9% to 1.8% relative to QEMU. Emulation overhead for SecureQEMU varies from 1400% to 2100% with respect to native performance. SecureQEMUs\u27 performance increase is negligible with respect to emulation overhead. Dependent on risk management strategy, SecureQEMU\u27s protection benefits may outweigh emulation overhead

Malware detection and analysis via layered annotative execution

Malicious software (i.e., malware) has become a severe threat to interconnected computer systems for decades and has caused billions of dollars damages each year. A large volume of new malware samples are discovered daily. Even worse, malware is rapidly evolving to be more sophisticated and evasive to strike against current malware analysis and defense systems. This dissertation takes a root-cause oriented approach to the problem of automatic malware detection and analysis. In this approach, we aim to capture the intrinsic natures of malicious behaviors, rather than the external symptoms of existing attacks. We propose a new architecture for binary code analysis, which is called whole-system out-of-the-box fine-grained dynamic binary analysis, to address the common challenges in malware detection and analysis. to realize this architecture, we build a unified and extensible analysis platform, codenamed TEMU. We propose a core technique for fine-grained dynamic binary analysis, called layered annotative execution, and implement this technique in TEMU. Then on the basis of TEMU, we have proposed and built a series of novel techniques for automatic malware detection and analysis. For postmortem malware analysis, we have developed Renovo, Panorama, HookFinder, and MineSweeper, for detecting and analyzing various aspects of malware. For proactive malware detection, we have built HookScout as a proactive hook detection system. These techniques capture intrinsic characteristics of malware and thus are well suited for dealing with new malware samples and attack mechanisms

A Deep Dive into Technical Encryption Concepts to Better Understand Cybersecurity & Data Privacy Legal & Policy Issues

Lawyers wishing to exercise a meaningful degree of leadership at the intersection of technology and the law could benefit greatly from a deep understanding of the use and application of encryption, considering it arises in so many legal scenarios. For example, in FTC v. Wyndham1 the defendant failed to implement nearly every conceivable cybersecurity control, including lack of encryption for stored data, resulting in multiple data breaches and a consequent FTC enforcement action for unfair and deceptive practices. Other examples of legal issues requiring use of encryption and other technology concepts include compliance with security requirements of GLBA & HIPAA, encryption safe harbors relative to state data breach notification laws and the CCPA, the NYDFS Cybersecurity Regulation, and PCI standards. Further, some policy discussions have taken place in 2020 regarding encrypted DNS over HTTPS, and lawyers would certainly seem to benefit from a better understanding of relevant encryption concepts to assess the privacy effectiveness of emerging encryption technologies, such as encrypted DNS. Finally, the need for technology education for lawyers is evidenced by North Carolina and Florida requiring one or more hours in technology CLE and New York in 2020 moving toward required CLE in the area of cybersecurity specifically. This article observes that there is a continuing desire for strong encryption mechanisms to advance the privacy interests of civilians’ online activities/communications (e.g., messages or web browsing). Law enforcement advocates for a “front door,” requiring tech platforms to maintain a decryption mechanism for online data, which they must produce upon the government providing a warrant. However, privacy advocates may encourage warrant-proof encryption mechanisms where tech platforms remove their ability to ever decrypt. This extreme pro-privacy position could be supported based on viewing privacy interests under a lens such as Blackstone’s ratio. Just as the Blackstone ratio principle favors constitutional protections that allow ten guilty people to go free rather than allowing one innocent person suffer, individual privacy rights could arguably favor fairly unsurveillable encrypted communications at the risk of not detecting various criminal activity. However, given that the internet can support large-scale good or evil activity, law enforcement continues to express a desire for a front door required by legislation and subject to suitable privacy safeguards, striking a balance between strong privacy versus law enforcement’s need to investigate serious crimes. In the last few decades, law enforcement appears to have lost the debate for various reasons, but the debate will likely continue for years to come. For attorneys to exercise meaningful leadership in evaluating the strength of encryption technologies relative to privacy rights, attorneys must generally understand encryption principles, how these principles are applied to data at rest (e.g., local encryption), and how they operate with respect to data in transit. Therefore, this article first explores encryption concepts primarily with regard to data at rest and then with regard to data in transit, exploring some general networking protocols as context for understanding how encryption can applied to data in transit, protecting the data payload of a packet and/or the routing/header information (i.e., the “from” and “to” field) of the packet. Part 1 of this article briefly explores the need for lawyers to understand encryption. Part 2 provides a mostly technical discussion of encryption concepts, with some legal concepts injected therein. Finally, Part 3 provides some high level legal discussion relevant to encryption (including arguments for and against law enforcement’s desire for a front door). To facilitate understanding for a non-technical legal audience, I include a variety of physical world analogies throughout (e.g., postal analogies and the like)