Larry A. Dunning

Privacy Preserving Data Sharing With Anonymous ID Assignment

An algorithm for anonymous sharing of private data among N parties is developed. This technique is used iteratively to assign these nodes ID numbers ranging from 1 to N. This assignment is anonymous in that the identities received are unknown to the other members of the group. Resistance to collusion among other members is verified in an information theoretic sense when private communication channels are used. This assignment of serial numbers allows more complex data to be shared and has applications to other problems in privacy preserving data mining, collision avoidance in communications and distributed database access. The required computations are distributed without using a trusted central authority. Existing and new algorithms for assigning anonymous IDs are examined with respect to trade-offs between communication and computational requirements. The new algorithms are built on top of a secure sum data mining operation using Newtons identities and Sturms theorem. An algorithm for distributed solution of certain polynomials over finite fields enhances the scalability of the algorithms. Markov chain representations are used to find statistics on the number of iterations required, and computer algebra gives closed form results for the completion rates.

A close look at task assignment in distributed systems

C. C. Shen and W. H. Tsai (IEEE Trans. Comput., vol.C-34, no.3, p.197-203 1985) proposed a graph matching algorithm for solving the static task assignment problem. It combines two important ideas: (1) graph homomorphism and (2) application of the A* algorithm. Task-dependent information is used as a heuristic to reduce the search effort in finding an optimal path to the goal node. An examination is made of Shen and Tsais strategy and their complexity measure. The authors propose some simple alternatives to their algorithm that are effective in reducing the number of nodes generated (and expanded) without sacrificing the optimality criteria.<<ETX>>

SEC-BED-DED Codes for Error Control in Byte-Organized Memory Systems

SEC-ED-DED codes are single error correcting and double error detecting while simultaneously providing byte error detection. SEC-BED-DED codes are constructed for byte lengths of 5 and larger. For many byte lengths and code lengths, these codes require fewer check bits or have implementation advantages when compared to other SEC-BED-DED codes.

Unidirectional byte error detecting codes for computer memory systems

Codes are developed for detecting unidirectional errors in t bytes simultaneously (t-UBED) while also providing all unidirectional error detection (AUED). These classes of codes differ from purely all unidirectional error detecting codes in that the errors in one byte may be of the form 1 to 0, while in another byte they may be of the form 0 to 1. The codes utilize 2 B for parity check information. As an example, a code providing 3-UBED+AUED protection for up to 12 information bytes of 8 b each can be constructed. >

Encoding and decoding for the minimization of message symbol error rates in linear block codes

Given any fixed linear block code, the error rates for the message symbols depend both on the encoding function and on the decoding map. This research shows how to optimize the choice of a generator matrix and decoding map simultaneously to minimize the error rates for all message symbols. The model used assumes that the distribution of messages is flat and that the distribution of error vectors defining the channel is independent of the message transmitted. In addition, it is shown that, with proper choice of coset leaders, standard array decoding is optimal in this circumstance. The results generalize previously known results on unequal error protection and are sufficiently general to apply when a code is used for error detection only.

Unidirectional 9-bit byte error detecting codes for computer memory systems

Codes are developed for detecting unidirectional errors in t bytes simultaneously (t-UBED). Some of the codes constructed also provide all unidirectional error detection (AUED). These classes of codes are different from AUED codes in that the errors in one byte may be of the form 1 to 0 while in another byte they may be of the form 0 to 1. The codes developed are for bytes of length nine consisting of eight data bits and one parity bit and utilize one byte for parity check information in addition to the parity check bits. Under various assumptions, codes varying in protection from 2-UBED to 4-UBED and 2-UBED+AUED to 3-UBED+AUED are constructed.<<ETX>>

Anonymous ID Assignment and Opt-Out

The networked society places great demand on the dissemination and sharing of private data. As privacy concerns grow, anonymity of communications becomes important. This paper addresses the issue of anonymous ID assignment to nodes in a distributed network and how it can be integrated with secure mining algorithms to allow nodes, that have privacy concerns, a capability to opt out of the mining computation. We propose two algorithms for ID assignment and evaluate their performance. We use them in the design of a protocol that allows a node to opt out of data mining, and investigate the collusion resistance capability of the resulting protocol.

A SEC-BED-DED code with byte plus bit error detection

A code is presented which is designed to protect a 64 bit word, consisting of 8 bytes of 8 bits each, against both byte errors and single bit errors occurring in computer memories. Two check bytes are appended to give an overall length of 80 bits. The code then provides the often studied SEC-BED-DED level of error protection; that is, single error correction, byte error detection and double error detection are available simultaneously. In addition, the code detects a byte error together with a single random error occurring concurrently in another byte. Some implementation issues such as systematic versus separable encoding are considered.<<ETX>>

Multiple error detection/correction using the Nordstrom-Robinson code

The non-linear Nordstrom-Robinson code of length 16 and minimum distance 6 has twice the codewords of any 16-bit linear code. The NR code is handled as though it were a linear code over Z/sub 4/ (the integers mod 4). Z/sub 4/ linearity is used here to evaluate the NR code itself along with the Hamming code and a (12, 8) used to detect 2-bit adjacent errors over 4-bit symbols.

A heuristic cost estimation method for optimizing assignment of tasks to processors

This paper concerns optimal static assignment of a group of communicating tasks among a set of processors. The assignment is based on Shen and Tsai’s [I] criteria for optimizing the completion time (or delay) of the task group. The delay criteria enhances parallelism by spreading the computation or load across multiple processors. In this paper we discuss the application of a heuristic cost estimation method that results in a speed up in solving the delay optimization problem. We use an example to demonstrate our approach and make observations based on running a large number of data sets using the proposed scheme.