On the decidability of self-assembly of infinite ribbons

IEEE Trans. Dependable and Secure Comput.

Medvidović

2013

Abstract-We present sTile, a technique for distributing trust-needing computation onto insecure networks, while providing probabilistic guarantees that malicious agents that compromise parts of the network cannot learn private data. With sTile, we explore the fundamental cost of achieving privacy through data distribution and bound how much less efficient a privacy-preserving system is than a nonprivate one. This paper focuses specifically on NP-complete problems and demonstrates how sTile-based systems can solve important real-world problems, such as protein folding, image recognition, and resource allocation. We present the algorithms involved in sTile and formally prove that sTile-based systems preserve privacy. We develop a reference sTile-based implementation and empirically evaluate it on several physical networks of varying sizes, including the globally distributed PlanetLab testbed. Our analysis demonstrates sTile's scalability and ability to handle varying network delay, as well as verifies that problems requiring privacypreservation can be solved using sTile orders of magnitude faster than using today's state-of-the-art alternatives.

Section: Computing With Tilesmentioning

confidence: 99%

Section: Efficiencymentioning

confidence: 99%

Entrusting Private Computation and Data to Untrusted Networks

IEEE Trans. Dependable and Secure Comput.

Medvidović

2013

“…Adleman et al (Adleman et al 2002b) showed that the tile assembly model with s = 1 is Turing-universal.…”

Section: Tile Assembly Model Definitionsmentioning

confidence: 99%

“…Specifically, self-assembly is the process of simple objects coming together and combining to form complex structures. Computer scientists and nanotechnologiests are interested in studying self-assembly because it is capable of computing functions (Adleman 2000; Adleman et al 2002b;Berger 1966;Winfree 1998b), assembling complex shapes (Adleman et al 2002a;Rothemund and Winfree 2000;Soloveichik and Winfree 2007), and guiding distributed robotics systems (Abelson et al 2000;Brun and Reishus 2009;McLurkin et al 2006). …”

Section: Introductionmentioning

confidence: 99%

Efficient 3-SAT algorithms in the tile assembly model

2012

Nat Comput

Self-assembly is a powerful process found in nature that guides simple objects assembling, on their own, into complex structures. Self-assembly is of interest to computer scientists because self-assembling systems can compute functions, assemble shapes, and guide distributed robotics systems. The tile assembly model is a formal mathematical model of self-assembly that allows the study of time and space complexities of self-assembling systems that lie at the heart of several molecular computer implementations and distributed computational software systems. These implementations and systems require efficient tile systems with small tilesets and fast execution times. The state of the art, however, requires vastly complex tile systems with large tilesets to implement fast algorithms. In this paper, I present S FS ; a tile system that decides 3-SAT by creating O H ð1:8393 n Þ nondeterministic assemblies in parallel, improving on the previous best known solution that requires Hð2 n Þ such assemblies. This solution directly improves the feasibility of building molecular 3-SAT solvers and efficiency of distributed software. I formally prove the correctness of the system, the number of required parallel assemblies, that the size of the system's tileset is 147 ¼ Hð1Þ; and that the assembly time is nondeterministic linear in the size of the input.

“…Tiles can stick together under certain conditions when their abutting sides' labels match. The tile assembly model has been shown to be Turing universal [2,23]. The tile assembly model is a computational model that is somewhat similar to cellular automata, but instead of being able to switch state, the individual square "automata" (called "tiles" precisely because they cannot change state) attach to other tiles following simple matching rules.…”

Section: Tile Architectural Stylementioning

confidence: 99%

Fault and adversary tolerance as an emergent property of distributed systems' software architectures

Proceedings of the 2007 Workshop on Engineering Fault Tolerant Systems

Medvidović

2007

Fault and adversary tolerance have become not only desirable but required properties of software systems because mission-critical systems are commonly distributed on large networks of insecure nodes. In this paper, we describe how the tile style, an architectural style designed to distribute computation, can inject fault and adversary tolerance. The result is a notion of tolerance that is entirely abstracted away from the functional properties of the software system. The client may specify what fraction of the network is faulty or malicious (e.g., 25%) and the acceptable system failure rate (e.g., 2−10 ), and the system's architecture adjusts automatically to ensure a failure rate no higher than the one specified. The technique is entirely automated and consists of a "smart redundancy" mechanism that brings the failure rate exponentially close to 0 by slowing down the execution speed linearly.