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On Optimal Hash Tree Traversal for Interval Time-Stamping [chapter]

Helger Lipmaa
2002 Lecture Notes in Computer Science  
Skewed trees constitute a two-parameter family of recursively constructed trees. Recently, Willemson proved that suitably picked skewed trees are space-optimal for interval time-stamping.  ...  At the same time, Willemson proposed a practical but suboptimal algorithm for nonrecursive traversal of skewed trees.  ...  We would like to thank Ahto Buldas, Markus Jakobsson, Jan Willemson and anonymous referees for useful comments.  ... 
doi:10.1007/3-540-45811-5_28 fatcat:s3cs4ehjpngqlb6tefr45ard44

Authentic Time-Stamps for Archival Storage [chapter]

Alina Oprea, Kevin D. Bowers
2009 Lecture Notes in Computer Science  
The data structure, an appendonly persistent authenticated dictionary, allows for efficient proofs of existence and non-existence, improving on state-of-the-art techniques.  ...  We study the problem of authenticating the content and creation time of documents generated by an organization and retained in archival storage.  ...  The authors also thank the anonymous reviewers from ESORICS 2009 for their comments and guidance on preparing the final version of the paper.  ... 
doi:10.1007/978-3-642-04444-1_9 fatcat:i5xi377tsvblfh5hf56oofivu4

Cache-efficient sweeping-based interval joins for extended Allen relation predicates

Danila Piatov, Sven Helmer, Anton Dignös, Fabio Persia
2021 The VLDB journal  
In an experimental evaluation, we show that our approach is several times faster and scales better than state-of-the-art techniques, while being much better suited for real-time event processing.  ...  Our technique is based on a framework, components of which can be flexibly combined in different manners to support the required interval relation.  ...  -At the core of this framework sits one base algorithm, called interval-time stamp join, that can be parameterized using a set of iterators traversing a Timeline Index.  ... 
doi:10.1007/s00778-020-00650-5 fatcat:h5vsihn2tvgerjolqkizvu73hy

Secure History Preservation Through Timeline Entanglement [article]

Petros Maniatis, Mary Baker
2002 arXiv   pre-print
Timeline entanglement is a sound method to map a time step in the history of one service onto the timeline of another, and helps clients of entangled services to get persistent temporal proofs for services  ...  In this paper we present the design and implementation of Timeweave, our service development framework for timeline entanglement based on two novel disk-based authenticated data structures.  ...  T 3 T 2 T 1 T h h 0 S 1 S 2 S 0 d 1 d 2 d each publication interval consists of a hash-tree of all published revocation records. The root hash of the CRT is a one-way digest of the database.  ... 
arXiv:cs/0202005v1 fatcat:xkva6j4t7vc5jl2zq2a6qzdtpe

An online algorithm for generating fractal hash chains applied to digital chains of custody [article]

Phillip G. Bradford, Daniel A. Ray
2007 arXiv   pre-print
This compact representation is useful to generate, traverse, and store a number of large digital hash chains on a small and constrained device.  ...  Our online algorithm for hash chain traversal incrementally generates a hash chain of n hash elements without knowledge of n before it starts.  ...  ., hash chain based protocols) compared to hash-and-sign time-stamping protocols. Building on work of Willemson [28] , Lipmaa [18] gives efficient algorithms to traverse skewed trees.  ... 
arXiv:0705.2876v1 fatcat:ksaxbze5kvea3ic7grjdir4wui

A Hybrid Spatio-Temporal Data Indexing Method for Trajectory Databases

Shengnan Ke, Jun Gong, Songnian Li, Qing Zhu, Xintao Liu, Yeting Zhang
2014 Sensors  
A new spatio-temporal interval criterion and a new node-choosing sub-algorithm are also proposed to optimize spatio-temporal R-tree structures.  ...  Furthermore, a database storage scheme based on a NoSQL-type DBMS is also proposed for the purpose of cloud storage.  ...  Songnian Li and Qing Zhu contribute a lot to the modification and optimization of this algorithm and index structures. Xintao Liu and Yeting Zhang help design and adjust the experimental schemes.  ... 
doi:10.3390/s140712990 pmid:25051028 pmcid:PMC4168421 fatcat:hzmty7jynzf4nnrnbhckpiyw6m

Fractal Merkle Tree Representation and Traversal [chapter]

Markus Jakobsson, Tom Leighton, Silvio Micali, Michael Szydlo
2003 Lecture Notes in Computer Science  
We introduce a technique for traversal of Merkle trees, and propose an efficient algorithm that generates a sequence of leaves along with their associated authentication paths.  ...  For one choice of parameters, and a total of N leaves, our technique requires a worst-case computational effort of 2 log N/loglog N hash function evaluations per output, and a total storage capacity of  ...  Acknowledgments We wish to thank Ari Juels for providing helpful feedback towards making the paper easier to read.  ... 
doi:10.1007/3-540-36563-x_21 fatcat:h52juzvanjbdfnoqo4wd6ytblu

Persistency in Suffix Trees with Applications to String Interval Problems [chapter]

Tsvi Kopelowitz, Moshe Lewenstein, Ely Porat
2011 Lecture Notes in Computer Science  
A collection of such problems is that of queries on string intervals of the text indexed by the suffix tree.  ...  Persistency can be utilized to obtain solutions for these problems on prefixes of the text, by solving these problems on previous versions of the suffix tree.  ...  Say that node u is stamped at time τ if u τ is created. Lemma 1. For every node u which is stamped at time τ there exists at most one child v that is also stamped at time τ .  ... 
doi:10.1007/978-3-642-24583-1_8 fatcat:jq4v4aclxbawjafdk6d5danbra

A New Timestamping Scheme Based on Skip Lists [chapter]

Kaouthar Blibech, Alban Gabillon
2006 Lecture Notes in Computer Science  
Time stamping is a cryptographic technique providing us with a proof-of-existence of a message/document at a given time. Several timestamping schemes have already been proposed [1-10].  ...  In this paper, we first define a new timestamping scheme which is based on skip lists [11] . Then, we show that our scheme offers nice properties and optimal performances.  ...  However, when compared to other schemes based on Merkle trees, it still has larger time complexity for both timestamping and verification due to the additional concatenation operations.  ... 
doi:10.1007/11751595_43 fatcat:2tosgufluzekhhrdlgftcayjyi

An Efficient Dynamic and Distributed Cryptographic Accumulator* [chapter]

Michael T. Goodrich, Roberto Tamassia, Jasminka Hasić
2002 Lecture Notes in Computer Science  
We describe a new scheme for authenticated dictionaries that supports efficient incremental updates of the underlying set and optimal constant-time verification by the user.  ...  Such usage implements the authenticated dictionary abstract data type and it finds applications in certificate management for public key infrastructure, and the publication of data collections on the Internet  ...  Acknowledgments We would like to thank Andrew Schwerin, Giuseppe Ateniese, and Douglas Maughan for several helpful discussions and e-mail exchanges relating to the topics of this paper.  ... 
doi:10.1007/3-540-45811-5_29 fatcat:q5agl4uejbhwvbdz3kxxl5o37u

Redesigning the string hash table, burst trie, and BST to exploit cache

Nikolas Askitis, Justin Zobel
2010 ACM Journal of Experimental Algorithmics  
For all the data structures, the expected cache costs of their array representations are superior to their standard and compact equivalents, even for the array hash, where on update, the asymptotic costs  ...  A search for around 28 million unique strings on a standard hash table that contains these strings, for example, can require over 2,300 seconds-using 2 15 slots-to complete while the table occupies almost  ...  operations, such as maintaining logs or time-stamped data, for example.  ... 
doi:10.1145/1671970.1921704 fatcat:eimxbg3zvjcpfefwa7jr7wx76i

An experimental analysis of self-adjusting computation

Umut A. Acar, Guy E. Blelloch, Matthias Blume, Kanat Tangwongsan
2006 Proceedings of the 2006 ACM SIGPLAN conference on Programming language design and implementation - PLDI '06  
Recent work on adaptive functional programming (AFP) developed techniques for writing programs that can respond to modifications to their data by performing change propagation.  ...  We show that the proposed approach is realistic by describing a library for self-adjusting computation, presenting efficient algorithms for realizing the library, and describing and evaluating an implementation  ...  represented with two time stamps, one for the start and one for the end.  ... 
doi:10.1145/1133981.1133993 dblp:conf/pldi/AcarBBT06 fatcat:tqavsfyjrjbpbo2nj57vrp7pyu

An experimental analysis of self-adjusting computation

Umut A. Acar, Guy E. Blelloch, Matthias Blume, Kanat Tangwongsan
2006 SIGPLAN notices  
Recent work on adaptive functional programming (AFP) developed techniques for writing programs that can respond to modifications to their data by performing change propagation.  ...  We show that the proposed approach is realistic by describing a library for self-adjusting computation, presenting efficient algorithms for realizing the library, and describing and evaluating an implementation  ...  represented with two time stamps, one for the start and one for the end.  ... 
doi:10.1145/1133255.1133993 fatcat:2nn4zxjjmrgjbgdl4ge73vhfgm

An experimental analysis of self-adjusting computation

Umut A. Acar, Guy E. Blelloch, Matthias Blume, Robert Harper, Kanat Tangwongsan
2009 ACM Transactions on Programming Languages and Systems  
Recent work on adaptive functional programming (AFP) developed techniques for writing programs that can respond to modifications to their data by performing change propagation.  ...  We show that the proposed approach is realistic by describing a library for self-adjusting computation, presenting efficient algorithms for realizing the library, and describing and evaluating an implementation  ...  represented with two time stamps, one for the start and one for the end.  ... 
doi:10.1145/1596527.1596530 fatcat:vmcusq2xdfb77mwxn5zimf52d4

Efficient Management of Short-Lived Data [article]

Albrecht Schmidt, Christian S. Jensen
2005 arXiv   pre-print
The algorithms are based on fully functional, persistent treaps, which are a combination of binary search trees with respect to a primary attribute and heaps with respect to a secondary attribute.  ...  In a number of applications, expiration times are known and can be assigned at insertion time. We present data structures and algorithms for online management of data tagged with expiration times.  ...  Acknowledgements The authors would like to thank Peter Schartner for helpful comments and pointers as well as Laurynas Speicys, SimonasŠaltenis and Kristian Torp for helpful discussions and their collaboration  ... 
arXiv:cs/0505038v1 fatcat:lf2spozujneevdljxy2xopcf5a
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