PKI Scalability Issues

This report surveys different PKI technologies such as PKIX and SPKI and the issues of PKI that affect scalability. Much focus is spent on certificate revocation methodologies and status verification systems such as CRLs, Delta-CRLs, CRS, Certificate Revocation Trees, Windowed Certificate Revocation, OCSP, SCVP and DVCS.Comment: 23 pages, 2 figure

Sharing Computer Network Logs for Security and Privacy: A Motivation for New Methodologies of Anonymization

Logs are one of the most fundamental resources to any security professional. It is widely recognized by the government and industry that it is both beneficial and desirable to share logs for the purpose of security research. However, the sharing is not happening or not to the degree or magnitude that is desired. Organizations are reluctant to share logs because of the risk of exposing sensitive information to potential attackers. We believe this reluctance remains high because current anonymization techniques are weak and one-size-fits-all--or better put, one size tries to fit all. We must develop standards and make anonymization available at varying levels, striking a balance between privacy and utility. Organizations have different needs and trust other organizations to different degrees. They must be able to map multiple anonymization levels with defined risks to the trust levels they share with (would-be) receivers. It is not until there are industry standards for multiple levels of anonymization that we will be able to move forward and achieve the goal of widespread sharing of logs for security researchers.Comment: 17 pages, 1 figur

FLAIM: A Multi-level Anonymization Framework for Computer and Network Logs

FLAIM (Framework for Log Anonymization and Information Management) addresses two important needs not well addressed by current log anonymizers. First, it is extremely modular and not tied to the specific log being anonymized. Second, it supports multi-level anonymization, allowing system administrators to make fine-grained trade-offs between information loss and privacy/security concerns. In this paper, we examine anonymization solutions to date and note the above limitations in each. We further describe how FLAIM addresses these problems, and we describe FLAIM's architecture and features in detail.Comment: 16 pages, 4 figures, in submission to USENIX Lis

Known-Plaintext Attack Against a Permutation Based Video

One of the approaches to deliver real-time video encryption is to apply permutations to the bytes within a frame of a fully encoded MPEG stream as presented in [2]. We demonstrate that this particular algorithm is vulnerable to a known-plaintext attack, and hence its use should be carefully considered. We also discuss modifications that can make the algorithm resistant to our attack

2015 XSEDE Federation Risk Assessment Overview

The methodology and working documentation for performing the 2012 and 2015 XSEDE Security Risk Assessments.NSF #1053575Ope

XSEDE Enterprise Services

Through acceptance of the XSEDE Level 1 SP Security Agreement and other contracts, providers of XSEDE central services agree to follow this security baseline document approved by the XSEDE Security Working Group (XSWoG). Because of the natural trust relationships between major XSEDE resources and the interdependence of them, security vulnerabilities affect far more than a single service provider. Therefore, this document sets forth minimum, security standards for providers of central services whose compromise could have a direct impact upon XSEDE. The list of security controls comes both from inherited practices of TeraGrid and new findings in the XSEDE risk assessment.National Science Foundation ACI-1548562Ope

Using a Specification-based Intrusion Detection System to Extend the DNP3 Protocol with Security Functionalities

Modern SCADA systems are increasingly adopting Internet technologies to control distributed industrial assets. As proprietary communication protocols are increasingly being used over public networks without efficient protection mechanisms, it is increasingly easier for attackers to penetrate into the communication networks of companies that operate electrical power grids, water plants, and other critical infrastructure systems. To provide protection against such attacks without changing legacy configurations, SCADA systems require an intrusion detection technique that can understand information carried by network traffic based on proprietary SCADA protocols. To achieve that goal, we adapted Bro, a specification-based intrusion detection system, for SCADA protocols in our previous work. In that work, we built into Bro a new parser to support DNP3, a complex proprietary network protocol that is widely used in SCADA systems for electrical power grids. The built-in parser provides clear visibility of network events related to SCADA systems. The semantics associated with the events provide us with a fine-grained operational context of the SCADA system, including types of operations and their parameters. Based on such information, we propose in this work two security policies to perform authentication and integrity checking on observed SCADA network traffic. To evaluate the proposed security policies, we simulated SCADA-specific attack scenarios in a test-bed, including real proprietary devices used in an electrical power grid. Experiments showed that the proposed intrusion detection system with the security policies can work efficiently in a large industry control environment that can include approximately 4000 devices.U.S. Department of Energy / DE-OE0000097National Science Foundation / OCI-1032889Infosys LimitedThe Boeing CompanyOpe

Preserving Both Privacy and Utility in Network Trace Anonymization

As network security monitoring grows more sophisticated, there is an increasing need for outsourcing such tasks to third-party analysts. However, organizations are usually reluctant to share their network traces due to privacy concerns over sensitive information, e.g., network and system configuration, which may potentially be exploited for attacks. In cases where data owners are convinced to share their network traces, the data are typically subjected to certain anonymization techniques, e.g., CryptoPAn, which replaces real IP addresses with prefix-preserving pseudonyms. However, most such techniques either are vulnerable to adversaries with prior knowledge about some network flows in the traces, or require heavy data sanitization or perturbation, both of which may result in a significant loss of data utility. In this paper, we aim to preserve both privacy and utility through shifting the trade-off from between privacy and utility to between privacy and computational cost. The key idea is for the analysts to generate and analyze multiple anonymized views of the original network traces; those views are designed to be sufficiently indistinguishable even to adversaries armed with prior knowledge, which preserves the privacy, whereas one of the views will yield true analysis results privately retrieved by the data owner, which preserves the utility. We present the general approach and instantiate it based on CryptoPAn. We formally analyze the privacy of our solution and experimentally evaluate it using real network traces provided by a major ISP. The results show that our approach can significantly reduce the level of information leakage (e.g., less than 1\% of the information leaked by CryptoPAn) with comparable utility