Entries Tagged "academic papers"

Page 74 of 74

SHA Cryptanalysis Paper Online

In February, I wrote about a group of Chinese researchers who broke the SHA-1 hash function. That posting was based on short notice from the researchers. Since then, many people have written me asking about the research and the actual paper, some questioning the validity of the research because of the lack of documentation.

The paper did exist; I saw a copy. They will present it at the Crypto conference in August. I believe they didn’t post it because Crypto requires that submitted papers not be previously published, and they misunderstood that to mean that it couldn’t be widely distributed in any way.

Now there’s a copy of the paper on the web. You can read “Finding Collisions in the Full SHA-1,” by Xiaoyun Wang, Yiqun Lisa Yin, and Hongbo Yu, here.

Posted on June 24, 2005 at 12:46 PMView Comments

Defining "Access" in Cyberspace

I’ve been reading a lot of law journal articles. It’s interesting to read legal analyses of some of the computer security problems I’ve been wrestling with.

This is a fascinating paper on the concepts of “access” and “authorized access” in cyberspace. The abstract:

In the last twenty-five years, the federal government and all fifty states have enacted new criminal laws that prohibit unauthorized access to computers. These new laws attempt to draw a line between criminality and free conduct in cyberspace. No one knows what it means to access a computer, however, nor when access becomes unauthorized. The few courts that have construed these terms have offered divergent interpretations, and no scholars have yet addressed the problem. Recent decisions interpreting the federal statute in civil cases suggest that any breach of contract with a computer owner renders use of that computer an unauthorized access. If applied to criminal cases, this approach would broadly criminalize contract law on the Internet, potentially making millions of Americans criminals for the way they write e-mail and surf the Web.

This Article presents a comprehensive inquiry into the meaning of unauthorized access statutes. It begins by explaining why legislatures enacted unauthorized access statutes, and why early beliefs that such statutes solved the problem of computer misuse have proved remarkably naïve. Next, the Article explains how the courts have construed these statutes in an overly broad way that threatens to criminalize a surprising range of innocuous conduct involving computers. In the final section, the Article offers a normative proposal for interpreting access and authorization. This section argues that courts should reject a contract theory of authorization, and should narrow the scope of unauthorized access statutes to circumvention of code-based restrictions on computer privileges. The section justifies this proposal on several grounds. First, the proposal will best mediate the line between securing privacy and protecting the liberty of Internet users. Second, the proposal mirrors criminal law’s traditional treatment of crimes that contain a consent element. Third, the proposed approach is consistent with the basic theories of punishment. Fourth, the proposed interpretation avoids possible constitutional difficulties that may arise under the broader constructions that courts recently have favored.

It’s a long paper, but I recommend reading it if you’re interested in the legal concepts.

Posted on June 14, 2005 at 7:16 AMView Comments

Wi-Fi Liabilities

Interesting law review article:

Suppose you turn on your laptop while sitting at the kitchen table at home and respond OK to a prompt about accessing a nearby wireless Internet access point owned and operated by a neighbor. What potential liability may ensue from accessing someone else’s wireless access point? How about intercepting wireless connection signals? What about setting up an open or unsecured wireless access point in your house or business? Attorneys can expect to grapple with these issues and other related questions as the popularity of wireless technology continues to increase.

This paper explores several theories of liability involving both the accessing and operating of wireless Internet, including the Computer Fraud and Abuse Act, wiretap laws, as well as trespass to chattels and other areas of common law. The paper concludes with a brief discussion of key policy considerations.

Posted on April 21, 2005 at 9:16 AMView Comments

A Taxonomy of Privacy

Interesting law review paper by Daniel Solove. Here’s the abstract:

Privacy is a concept in disarray. Nobody can articulate what it means. As one commentator has observed, privacy suffers from “an embarrassment of meanings.” Privacy is far too vague a concept to guide adjudication and lawmaking, as abstract incantations of the importance of “privacy” do not fare well when pitted against more concretely-stated countervailing interests.

In 1960, the famous torts scholar William Prosser attempted to make sense of the landscape of privacy law by identifying four different interests. But Prosser focused only on tort law, and the law of information privacy is significantly more vast and complex, extending to Fourth Amendment law, the constitutional right to information privacy, evidentiary privileges, dozens of federal privacy statutes, and hundreds of state statutes. Moreover, Prosser wrote over 40 years ago, and new technologies have given rise to a panoply of new privacy harms.

A new taxonomy to understand privacy violations is thus sorely needed. This article develops a taxonomy to identify privacy problems in a comprehensive and concrete manner. It endeavors to guide the law toward a more coherent understanding of privacy and to serve as a framework for the future development of the field of privacy law.

The paper is a follow-on to his previous paper, “Conceptualizing Privacy.”

Posted on April 19, 2005 at 1:32 PMView Comments

Remote Physical Device Fingerprinting

Here’s the abstract:

We introduce the area of remote physical device fingerprinting, or fingerprinting a physical device, as opposed to an operating system or class of devices, remotely, and without the fingerprinted device’s known cooperation. We accomplish this goal by exploiting small, microscopic deviations in device hardware: clock skews. Our techniques do not require any modification to the fingerprinted devices. Our techniques report consistent measurements when the measurer is thousands of miles, multiple hops, and tens of milliseconds away from the fingerprinted device, and when the fingerprinted device is connected to the Internet from different locations and via different access technologies. Further, one can apply our passive and semi-passive techniques when the fingerprinted device is behind a NAT or firewall, and also when the device’s system time is maintained via NTP or SNTP. One can use our techniques to obtain information about whether two devices on the Internet, possibly shifted in time or IP addresses, are actually the same physical device. Example applications include: computer forensics; tracking, with some probability, a physical device as it connects to the Internet from different public access points; counting the number of devices behind a NAT even when the devices use constant or random IP IDs; remotely probing a block of addresses to determine if the addresses correspond to virtual hosts, e.g., as part of a virtual honeynet; and unanonymizing anonymized network traces.

And an article. Really nice work.

Posted on March 7, 2005 at 3:02 PMView Comments

Flaw in Pin-Tumbler Locks

This paper by Barry Wels and Rop Gonggrijp describes a security flaw in pin tumbler locks. The so called “bump-key” method will open a wide range of high security locks in little time, without damaging them.

It’s about time physical locks be subjected to the same open security analysis that computer security systems have been. I would expect some major advances in technology as a result of all this work.

Posted on March 7, 2005 at 7:27 AMView Comments

1 72 73 74

Sidebar photo of Bruce Schneier by Joe MacInnis.