PPT-Hash Tables

CIS 606 Spring 2010 Hash tables Many applications require a dynamic set that supports only the dictionary operations INSERT SEARCH and DELETE Example a symbol table in a compiler A hash table is effective for implementing a dictionary. Exploiting the Entropy. in a Data Stream. Michael Mitzenmacher. Salil Vadhan. How Collaborations Arise…. At a talk on Bloom filters – a hash-based data structure.. Salil: Your analysis assumes perfectly random hash functions. What do you use in your experiments?. Mark Russinovich Technical Fellow. Microsoft Azure. Nathan Ide Principal Dev Lead. Microsoft Windows. Pass-the-Hash == Single-Sign On. Pass-the-hash is the use of a saved credential or authenticator . Motivating Applications. Large collection of datasets. Datasets are dynamic (insert, delete). Goal: efficient searching/insertion/deletion. Hashing is ONLY applicable for exact-match searching. Direct Address Tables. Comp 550. Dictionary . Dictionary:. Dynamic-set data structure for . storing items indexed using . keys. .. Supports . operations: Insert, Search, and . Delete . (. take . O. (1) time. ). .. Applications:. Message Authentication Codes. Sebastiaan. de Hoogh, . TU/e. Cryptography 1. September 12, 2013. Announcements. Until this morning 50 students handed in 43 pieces of . homeworks. . (only 7 pairs). BUT: . Passwords stored in computers are changed from their plain text form to an encrypted value.. These values are called hashes, and there is a unique plain text value for every hash.. A rainbow table is a lookup table offering a time-memory tradeoff used in recovering the plaintext password from a password hash generated by a hash function . Dominique Unruh. University of Tartu. Surprises with hash functions. Consider a hash function and a horse race. “Spicy Spirit” wins…. Commitments and hashes. Player. Bookie.  . Player. Bookie. Plan. I spent the last decade advising on numerous cases where hash tables/functions were used. A few observations on . What data structures I’ve seen implemented and where. What do developers think, were they need help. Kai Li, Guo-Jun Qi, Jun Ye, Tuoerhongjiang Yusuph, Kien A. Hua. Department of Computer Science. University of Central Florida. ISM 2016. Presented by . Tuoerhongjiang Yusuph. Introduction. Massive amount of high-dimensional data, high computational costs …. n. . . [from the . techspeak. ] (var. ‘hash clash’) . When used of people, signifies a confusion in associative memory or imagination, especially a persistent one.” . . -. The Hacker's Dictionary . Hash functions. (Cryptographic) hash function: deterministic function mapping arbitrary length inputs to a short, fixed-length output (sometimes called a . digest. ). Hash functions can be . keyed. or . Instructor: Lilian de Greef Quarter: Summer 2017 CSE 373: Data Structures and Algorithms Lecture 6: Finishing Amortized Analysis; Dictionaries ADT; Introduction to Hash Tables Today: Finish up Amortized Analysis Pass-The-Hash: Gaining Root Access to Your Network June 24, 2014 Tim Slaybaugh Cyber Incident Analyst Northrop Grumman Information Systems What is Pass-The-Hash? “Attackers using PtH completely compromise just about every network they hit. Pretty much every APT attack team uses them.” A common approach is to use a . Distributed Hash Table. (DHT). to organize . nodes. Traditional . hash functions convert a key to a hash value, which can be used as an index into a hash table.. Keys are unique.