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We apply results from algebraic coding theory to solve problems in cryptography, by using recent results on list decoding of error-correcting codes to efficiently find traitors who collude to create pirates. We produce schemes for which the traceability (TA) traitor tracing algorithm is very fast. We compare the TA and identifiable parent property (IPP) traitor tracing algorithms, and give evidence that when using an algebraic structure, the ability to trace traitors with the IPP algorithm implies the ability to trace with the TA algorithm. We also demonstrate that list decoding techniques can be used to find all possible pirate coalitions. Finally, we raise some related open questions about linear codes, and suggest uses for other decoding techniques in the presence of additional information about traitor behavior. Index Terms--Algebraic-geometry (AG) code, identifiable parent property (IPP), list decoding, Reed-Solomon code, traceability (TA) code, traitor tracing.

We construct certain error-correcting codes over finite rings and estimate their parameters. These codes are constructed using plane curves and the estimates for their parameters rely on constructing "lifts" of these curves and then estimating the size of certain exponential sums. Index Terms - Algebraic geometry, codes, codes over rings, plane curves.

The techniques of algebraic geometry have been widely and successfully applied to the study of linear codes over finite fields since the early 1980's. Recently, there has been an increased interest in the study of linear codes over finite rings. In a previous paper, we combined these two approaches to coding theory by introducing and studying algebraic-geometric codes over rings. In this correspondence, we show that the Nordstrom-Robinson code is the image under the Gray mapping of an algebraic geometric code over Z/4Z. Index Terms - Algebraic geometry, codes, Nordstrom-Robinson code.

Critical indecomposable codes were introduced by Assmus [1], who also gave a recursive construction for these objects. One of the key ingredients in the construction is an auxiliary code, which is an indecomposable code of minimum distance at least 3. In terms of actually being able to construct all critical indecomposable codes, however, Assmus leaves many unanswered questions about these auxiliary codes. In this paper, we provide answers to these questions, including a description of when two equivalent auxiliary codes can yield inequivalent critical indecomposable codes, and results on both the minimum length and the maximum number of critical columns of an auxiliary code. We end with an enumeration of all critical indecomposable codes of dimension at most 10. Index Terms--Automorphism group, canonical form, category, generator matrix, indecomposable, linear code.

Background: Health care-associated infections are serious complications impacting 2 million patients and accounting for approximately 100,000 deaths per year. In the present study, we evaluated the effectiveness of a new hand hygiene monitoring program (HHMP) and measured the sustainability of this effectiveness over a 1-year period., Methods: The HHMP consisted of 4 key components: extensive education, conspicuous and visible monitors, immediate feedback concerning compliance to health care workers, and real-time data dissemination to leadership. The HHMP was implemented in 2 hospital care units. Two different, but similar, departments served as controls, and hand hygiene compliance was monitored via the "secret shopper" technique. All 4 departments were followed for 12 months., Results: Both experimental departments showed statistically significant increases in hand hygiene compliance. Experimental department 1 increased compliance from 49% to an average of 90%, and experimental department 2 increased compliance from 60% to an average of 96%. Both experimental departments were able to sustain these results for at least 6 months. Compliance rates were significantly higher in the experimental departments compared with the control departments. No significant changes were seen in the control departments., Conclusions: These finding suggest that continuous monitoring by salient observers and immediate feedback are critical to the success of hand hygiene programs., (Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.)