Smart home devices are becoming increasingly complex and data-rich. The inevitable repair of these devices will be both difficult and privacy-sensitive. A "HandyTech"—a technician for home Internet of Things (IoT) system repair—has the potential to lower barriers to repair, but privacy questions remain: Are people willing to use a HandyTech to fix a broken home IoT device despite the inherent privacy risk (i.e., allowing a third party to access potentially sensitive IoT data)? We explore this question through a vignette-based, multi-factorial survey with a nationally representative sample of adults in the United States. We further ask whether types of devices (i.e., smart speakers, refrigerators, and CPAP machines) and factors adjacent to privacy and associated with the HandyTech's work (i.e., scope of access, state-based licensing requirements, and transparency provisions) affect decisions to use or not use a HandyTech. We find that some demographic groups are more willing than others to use a HandyTech (e.g., younger age groups, those with children in the home). Current ownership of more types of smart devices increases willingness to use a HandyTech, while greater concerns over general IoT privacy decreases willingness to use a HandyTech. Device-specific perceptions also mattered, such that perceived urgency to fix is strongly associated with willingness to use a HandyTech, but concern over that device's privacy is not. In addition, reduced scope of access and increased transparency by the HandyTech statistically increased willingness to use a HandyTech. In closing, we recommend takeaways that developers and policymakers can engage with to decrease privacy concerns and increase the adoption of third-party IoT repair.

Communications metadata can be used to determine a communication’s device, identify the user of the device, and profile the user’s personality and behavior. The current state of affairs is that the increase of attacks against user privacy based on using communications metadata vastly outpaces the ability of users to protect themselves. With few exceptions, protections are point solutions against a specific attack. In the current situation, the user loses.

Traditionally metadata, the who, when, where of a phone call, the IP address, time, date of an Internet connection, has been viewed as deserving of less privacy than the contents of the communication. But ubiquitous computing and communication has changed that equation, and such transactional information has become increasingly revelatory. In this talk, I will discuss how metadata is used in all sorts of investigations, from malware to malfeasance. I will also discuss how the ubiquity of metadata must mean a change in our approaches to it.

The past and the future of privacy and cybersecurity are addressed from four perspectives, by different authors: theory and algorithms, technology, policy, and economics. Each author considers the role of the threat from the corresponding perspective, and each adopts an individual tone, ranging from a relatively serious look at the prospects for improvement in underlying theory and algorithms to more lighthearted considerations of the unpredictable futures of policy and economics.

Government's role in computer science is much larger than funding agencies. Digital rights management, net neutrality, and cybersecurity are hot topics in Washington, hot topics where regulation or legislation may have major impact on the computer systems we develop and enjoy. Yet the rules governing DC are very different than the rules that govern science and engineering, and learning how to operate in a world where facts are only ten percent of the equation can be a challenging experience for someone more accustomed to proving theorems and building systems. I'll describe what it takes for a nerd to be effective in the world of government, and give some specific examples in the hot area of cyberwar.

Through legislation and technology the film industry has been seeking to fully control usage of the bits it creates; their model is "restrictive" digital-rights management (DRM) that only allows the user to view the film rather than copy, edit, or create new content. Meanwhile, the experience that the Internet generation has of interacting with, rather than consuming, content, could be the basis for a new business for Hollywood: films that enable users to interact directly by putting themselves (and others) into the movie. In this paper we examine massive multi-player online role-playing games (MMORPGs), in which players exercise design technologies and tools that further their roles and play. MMORPGs are rapidly gaining audience share. We posit that non-restrictive, or exible, digital-rights management is in the movie industry's economic interest.

Functional decomposition—whether a functionf(x) can be written as a composition of functionsg(h(x)) in a non-trivial way—is an important primitive in symbolic computation systems. The problem of univariate polynomial decomposition was shown to have an efficient solution by Kozen and Landau (1989). Dickerson (1987) and Gathen (1990a) gave algorithms for certain multivariate cases. Zippel (1991) showed how to decompose rational functions. In this paper, we address the issue of decomposition of algebraic functions. We show that the problem is related to univariate resultants in algebraic function fields, and in fact can be reformulated as a problem ofresultant decomposition. We characterize all decompositions of a given algebraic function up to isomorphism, and give an exponential time algorithm for finding a non-trivial one if it exists. The algorithm involves genus calculations and constructing transcendental generators of fields of genus zero.

Radical simplification is an important part of symbolic computation systems. Until now no algorithms were known for the general denesting problem. If the base field contains all roots of unity, then necessary and sufficient conditions for a denesting are given, and the algorithm computes a denesting of $\alpha $ when it exists. If the base field does not contain all roots of unity, then it is shown how to compute a denesting that is within one of optimal over the base field adjoining a single root of unity. Throughout this paper, a primitive lth root of unity is respresented by its symbol $\zeta_l $, rather than as a nested radical. The algorithms require computing the splitting field of the minimal polynomial of $\alpha $ over k, and have exponential running time.

Previous article Full AccessErratum: Factoring Polynomials over Algebraic Number FieldsSusan LandauSusan Landauhttps://doi.org/10.1137/0220061PDFBibTexSections ToolsAdd to favoritesExport CitationTrack CitationsEmail SectionsAbout"Erratum: Factoring Polynomials over Algebraic Number Fields." SIAM Journal on Computing, 20(5), p. 998[1] Susan Landau, Factoring polynomials over algebraic number fields, SIAM J. Comput., 14 (1985), 184–195 10.1137/0214015 86d:11102 0565.12002 LinkISIGoogle Scholar[2] S. Landau and , G. Miller, Solvability by radicals is in polynomial time, J. Comput. System Sci., 30 (1985), 179–208 10.1016/0022-0000(85)90013-3 86k:12001 0586.12002 CrossrefISIGoogle Scholar Previous article FiguresRelatedReferencesCited ByDetails Theoretical study of level structure and transitions of configurations 3d94s2 3d94s4p, 3d94p2 for Nb XIIIActa Physica Sinica, Vol. 62, No. 10 | 1 Jan 2013 Cross Ref Volume 20, Issue 5| 1991SIAM Journal on Computing History Submitted:22 May 1991Accepted:22 May 1991Published online:13 July 2006 InformationCopyright © 1991 Society for Industrial and Applied MathematicsPDF Download Article & Publication DataArticle DOI:10.1137/0220061Article page range:pp. 998-998ISSN (print):0097-5397ISSN (online):1095-7111Publisher:Society for Industrial and Applied Mathematics

This paper treats the following geometric problem: Given vertices $x_1 , \cdots ,x_n $ of a polyhedron in the integer lattice in k dimensions, can that polyhedron be “shrunk” to a similar one (i.e., one whose sides remain in the same ratio as the original polyhedron) while still remaining on the integer lattice? A necessary condition is given for this to be possible, which depends on the parity of k; for $k\leqq 4$ it is shown that the condition is sufficient, and algorithms are also given to do the shrinking. In two dimensions, the algorithm only involves computing greatest common divisors over the Gaussian integers and is polynomial time. For $k = 3$ and 4 the algorithms involve computing g.c.d.s in the algebra of Hurwitz quaternions. This gives a polynomial time algorithm for $k = 4$, but because the algorithm in three dimensions relies on determining the square factors of an integer, it is at present exponential. The proofs are remarkably simple and are quite computational in nature.

Radical simplification is a fundamental mathematical question, as well as an important part of symbolic computation systems. The general denesting problem had not been known to be decidable. Necessary and sufficient conditions for a radical alpha over a field k to be denested, as well as the first algorithm to decide whether the expression can be denested, are given. The algorithm computes an equivalent expression of minimum nesting depth. It has running time polynomial in the size of the splitting field of the minimal polynomial of alpha over k.>

We examine the question of when a polynomial f over a commutative ring has a nontrivial functional decomposition f=go h. Previous algorithms are exponential-time in the worst case, require polynomial factorization, and only work over fields of characteristic 0. We present an O(n2)-time algorithm, where r is the degree of g. We also show that the problem is in NC. The algorithm does not use polynomial factorization, and works over any commutative ring containing a multiplicative inverse of r. Finally, we give a new structure theorem that leads to necessary and sufficient algebraic conditions for decomposibility over any field. We apply this theorem to obtain an NC algorithm for decomposing irreducible polynomials over finite fields, and a subexponential algorithm for decomposing irreducible polynomials over any field admitting efficient polynomial factorization.

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We show that if $f(x)$ is a polynomial in $Z [ \alpha ][ x ]$, where $\alpha $ satisfies a monic irreducible polynomial over Z, then $f(x)$ can be factored over $Q(\alpha )[ x ]$ in polynomial time. We also show that the splitting field of $f(x)$ can be determined in time polynomial in ([Splitting field of $f(x): Q $], $\log | (x) |$).

Every high school student knows how to express the roots of a quadratic equation in terms of radicals; what is less well-known is that this solution was found by the Babylonians a millenia and a half before Christ [Ne]. Three thousand years elapsed before European mathematicians determined how to express the roots of cubic and quartic equations in terms of radicals, and there they stopped, for their techniques did not extend. Lagrange published a treatise which discussed why the methods that worked for polynomials of degree less than five did not work for quintic polynomials [Lag],