DOCSLIB.ORG

A Dynamical Systems Approach to the Discrimination of the Modes of Operation of Cryptographic Systems

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Dynamical Systems Approach to the Discrimination of the Modes of Operation of Cryptographic Systems A dynamical systems approach to the discrimination of the modes of operation of cryptographic systems Jeaneth Machicao∗ Scientific Computing Group, S~aoCarlos Institute of Physics, University of S~aoPaulo (USP), PO Box 369, 13560-970, S~aoCarlos, SP, Brazil - www.scg.ifsc.usp.br Jan M. Baetensy KERMIT, Department of Mathematical Modeling, Statistics and Bioinformatics, Ghent University, Coupure links 653, 9000 Ghent, Belgium - www.kermit.ugent.be Anderson G. Marco Scientific Computing Group, S~aoCarlos Institute of Physics, University of S~aoPaulo (USP), PO Box 369, 13560-970, S~aoCarlos, SP, Brazil - www.scg.ifsc.usp.br Bernard De Baetsz KERMIT, Department of Mathematical Modeling, Statistics and Bioinformatics, Ghent University, Coupure links 653, 9000 Ghent, Belgium - www.kermit.ugent.be Odemir M. Brunox Scientific Computing Group, S~aoCarlos Institute of Physics, University of S~aoPaulo (USP), PO Box 369, 13560-970, S~aoCarlos, SP, Brazil - www.scg.ifsc.usp.br (Dated: September 12, 2018) Evidence of signatures associated with cryptographic modes of operation is established. Motivated by some analogies between cryptographic and dynamical systems, in particular with chaos theory, we propose an algorithm based on Lyapunov exponents of discrete dynamical systems to estimate the divergence among ciphertexts as the encryption algorithm is applied iteratively. The results allow to distinguish among six modes of operation, namely ECB, CBC, OFB, CFB, CTR and PCBC using DES, IDEA, TEA and XTEA block ciphers of 64 bits, as well as AES, RC6, Twofish, Seed, Serpent and Camellia block ciphers of 128 bits. Furthermore, the proposed methodology enables a classification of modes of operation of cryptographic systems according to their strength. I. INTRODUCTION particular [5]. Since this major breakthrough, the functioning of The propagation and continuous flow of information the industrial, financial and public sector has become are of utter importance for the development of stable strongly dependent on the advances of cryptography. For economies throughout the world as they are a prerequi- instance, while the availability of worldwide networks has site for successful business transactions, short- and long- enabled rapid dissemination of information, it has also range communication, and so on [1]. Often this infor- stimulated cryptographic innovations because a signifi- mation has to be encrypted in such a way that it can cant share of this information may only be available to a be safely transferred between the sender and recipient few parties. In this manner, technological progress dur- without allowing others to read the information that ing the last decades has increased the need for secured is present in such an encrypted message [2]. On the communication and transactions, information shielding, arXiv:1504.02549v1 [cs.CR] 10 Apr 2015 other hand, malicious persons and organizations, but also and so on [3, 4]. governmental organizations, are continuously striving to In the last few decades, modern cryptography replaced break the key with which messages were encrypted be- mechanical schemes with new computing models. This cause this might enable them to get those pieces of in- modern focus influenced the classical design of ciphers formation that are needed to achieve their criminal, pro- far beyond the original purpose. Nowadays, there are tective, or other goals [3, 4]. It is probably due to the two class of cryptographic algorithms depending on the impact of Turing's success in breaking the Enigma that key: symmetric and asymmetric. Symmetric encryption humanity became aware of the importance of cryptogra- algorithms use the same key for both encryption of plain- phy in general, and the vulnerability of ciphers more in text and decryption of ciphertext. This class of algorithm is also divided into two categories: stream ciphers and block ciphers. Block ciphers have gained wide popular- ∗ [email protected] ity since the introduction of the first adopted encryp- y [email protected] tion: The Data Encryption Standard (DES) [6], in the z [email protected] mid-1970s, yet nowadays this cipher is considered prone x [email protected] to brute force attacks. To overcome this shortcoming 2 the International Data Encryption Algorithm (IDEA) [7] or asymptotically stable, respectively, or the system is was designed in 1991 to replace DES. Ever since, there conservative, which means that the initial separation re- has been a pursuit for the development of new algo- mains. rithms that meet the rising security expectations. In As the fields of cryptography and dynamical systems 1997, the National Institute of Standards and Technol- are not yet strongly interwoven, the basic definitions and ogy (NIST) [8] selected the official Advanced Encryption concepts that relate to those systems and that are of Standard (AES) among many competitors, namely Ser- interest within the framework of this paper are presented pent [9], Twofish [10], RC6 [11], Rijndael [12], etc. in Section II, while the dynamical systems viewpoint on To date, block ciphers are the most important ele- cryptographic systems is presented in Section III together ments in many cryptographic systems [3]. A block ci- with the proposed method for identifying the underlying pher breaks a message into blocks of elements (bits) and mode of operation. Finally, the strengths of the proposed then encrypts one block (plaintext) at a time producing method are illustrated and discussed in Section IV by its corresponding output block (ciphertext). However, a means of computer experiments. block cipher by itself allows for the encryption of only one block, such that it is recommended to use a mode of operation in conjunction [13]. This mode of opera- II. PRELIMINARIES tion specifies a mechanism to improve the corresponding block cipher, while encrypting all of the blocks, one by In this section we introduce the specificities of both one, as it goes along. cryptographic and dynamical systems that are indispens- Motivated by the analogies between cryptographic and able for a clear understanding this paper. dynamical systems, on the one hand, and the lack of a means to discriminate between different modes of opera- tion that can be used to encrypt a message with a block A. Block ciphers and modes of operation cipher using a single key, on the other hand, we demon- strate in this paper how Lyapunov exponents can be re- Classically, an encryption system encloses three major lied upon for tackling this problem. More specifically, components, namely a cipher, a key, and finally, a cipher- by contemplating the whole of a cipher, ciphertext and text. The former constitutes a sequence of instructions key as an utter discrete dynamical system, i.e., a cellular that must be executed in order to encrypt a given plain- automaton (CA), and by resorting to the notion of Lya- text, which may be envisaged as a sequence of N bits, punov exponents as they have been conceived for such such that it can be represented as a Boolean vector P of systems [14, 15], we show how these measures can be ex- length N. The result of this encryption process using a ploited to identify the mode of operation that was used key K, which is a sequence of k bits, is a so-called cipher- during the encryption process. text, which may be represented in a similar fashion as a Although the cryptographic process of encrypting and Boolean vector C of length N [3]. decrypting information does not constitute a dynamical Of course, the real plaintext size varies and is mostly system as such, it has been reported that it is possible different from the length of the blocks for which a block to draw parallels between cryptographic and dynamical cipher is designed. Consequently, common ciphers can- systems [16{19]. Hence, drawing upon such parallels, we not be applied directly for the encryption of arbitrary- have a means to exploit similar tools as the ones that have length plaintext [28]. In order to overcome this issue, been conceived in the framework of dynamical systems in so-called block ciphers have been designed and imple- order to characterize cryptographic systems. Taking into mented. A block cipher slices the plaintext of length N account that the stability of a dynamical system is gen- into b blocks of n bits, after which each of these blocks is erally acknowledged as its main characteristic because it encrypted/decrypted by a block cipher, denoted as EK −1 gives insight into its intrinsic nature [20, 21], it is natural and EK , respectively. Mathematically, the encryption to verify whether the dynamical systems viewpoint of a of a plaintext P = (P1;P2;:::;Pb) of length n into a cryptographic system allows for a similar notion in order ciphertext of the same length can be formalized as C = k n n to better understand the latter. An exploration of this E(K; P) = EK (P), where E : 0; 1 0; 1 0; 1 . is further motivated by the fact that several researchers If the length N of the plaintextf isg not×f a wholeg ! multiple f g have noticed a close resemblance between a cryptographic of b, additional bits are padded to the last block of the system on the one hand, and a chaotic system, on the plaintext. other hand [22{25], and the large number of chaos-based These block ciphers encrypt a plaintext in accordance cryptosystems [26, 27]. with a well-defined procedure, which is commonly re- Classically, the stability of a dynamical system is as- ferred to as the mode of operation of a block cipher. A sessed by computing its so-called largest Lyapunov expo- block cipher encrypts one block at a time, and it is the nent that quantifies how it behaves if it is evolved from mode of operation that allows a block cipher to encrypt two different but close initial conditions [20].
Load more

Recommended publications
  • Fault-Resilient Lightweight Cryptographic Block Ciphers for Secure Embedded Systems
    Rochester Institute of Technology RIT Scholar Works Theses 11-2014 Fault-Resilient Lightweight Cryptographic Block Ciphers for Secure Embedded Systems Kai Tian Follow this and additional works at: https://scholarworks.rit.edu/theses Recommended Citation Tian, Kai, "Fault-Resilient Lightweight Cryptographic Block Ciphers for Secure Embedded Systems" (2014). Thesis. Rochester Institute of Technology. Accessed from This Thesis is brought to you for free and open access by RIT Scholar Works. It has been accepted for inclusion in Theses by an authorized administrator of RIT Scholar Works. For more information, please contact [email protected]. Fault-Resilient Lightweight Cryptographic Block Ciphers for Secure Embedded Systems by Kai Tian A Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science in Electrical Engineering Supervised by Dr. Mehran Mozaffari-Kermani Department of Electrical and Microelectronic Engineering Kate Gleason College of Engineering Rochester Institute of Technology Rochester, NY November 2014 Approved By: Dr. Mehran Mozaffari-Kermani Assistant Professor – R.I.T. Dept. of Electrical and Microelectronic Engineering Dr. Dorin Patru Associate Professor – R.I.T. Dept. of Electrical and Microelectronic Engineering Dr. Reza Azarderakhsh Assistant Professor – R.I.T. Dept. of Computer Engineering Dr. Sohail A. Dianat Department Head - Professor –Dept. of Electrical and Microelectronic Engineering Acknowledgements I am grateful to my advisor, Dr. Mehran Mozaffari-Kermani, whose support and guidance helped me to understand the concepts clearly and complete my Masters. Special thanks also go to other professors, who helped me in my field of study, Dr. Dorin Patru, Dr. Reza Azarderakhsh and Dr. Marcin Lukowiak, for their constructive comments and participation.
    [Show full text]
  • Camellia: a 128-Bit Block Cipher Suitable for Multiple Platforms
    gopyright x nd witsuishi iletri gorp ortion PHHHEPHHI g mel l iX e IPVEfit flo k gipher uitle for wultiple ltforms y z y uzumro eoki etsuyshikw wsyuki und z y z z witsuru wtsui hiho worii tunkoxkjim oshio okit y xipp on elegrph nd elephone gorp ortion IEI rikrino okD okosukD ungwD PQWEHVRU tpn fmroDkndDshihogdislFnttFoFjp z witsuishi iletri gorp ortion SEIEI yfunD umkurD ungwD PRUEVSHI tpn fihikwDmtsuiDjuneISDtokitgdissFislFmeloFoFjp er IFHX tuly IQD PHHH er PFHX eptemer PTD PHHI estrtF e present new IPVEit lo k ipher lled gmel liF gmelli supp orts IPVEit lo ksizend IPVED IWPED nd PSTEit keysD iFeF the sme interfe sp eitions s the edvned inryption tndrd @eiAF iieny on oth softE wre nd hrdwre pltforms is remrkle hrteristi of gmelli in ddition to its high level of seurityF st is onrmed tht gmelli provides strong seurity ginst dierentil nd liner ryptnlysisF gompred to the ei nlistsD iFeF weD gTD ijndelD erp entD nd woshD gmelli oers t lest omprle enryption sp eed in softwre nd hrdwreF en optimized implementtion of gmelE li in ssemly lnguge n enrypt on entiums s s @IFIQqrzA t the rte of RUI wits p er seondF sn dditionD distinguishing feture is its smll hrdwre designF e hrdwre implementtionD whih inludes enryptionD deryptionD nd the key shedule for IPVEit keysD o upies only VFIPu gtes using HFIV"m gwy esg lirryF his is in the smllest lss mong ll existing IPVEit lo k iphersF gopyright x nd witsuishi iletri gorp ortion PHHHEPHHI gontents I sntro dution I P hesign tionle Q PFI p Efuntion X X X X X X X X X X X X X X X X X X X X X X X X X
    [Show full text]
  • Advanced Encryption Standard Real-World Alternatives
    Outline Multiple Encryption Birthday Attack Advanced Encryption Standard Real-World Alternatives CPSC 367: Cryptography and Security Michael Fischer Lecture 7 February 5, 2019 Thanks to Ewa Syta for the slides on AES CPSC 367, Lecture 7 1/58 Outline Multiple Encryption Birthday Attack Advanced Encryption Standard Real-World Alternatives Multiple Encryption Composition Group property Birthday Attack Advanced Encryption Standard AES Real-World Issues Alternative Private Key Block Ciphers CPSC 367, Lecture 7 2/58 Outline Multiple Encryption Birthday Attack Advanced Encryption Standard Real-World Alternatives Multiple Encryption CPSC 367, Lecture 7 3/58 Outline Multiple Encryption Birthday Attack Advanced Encryption Standard Real-World Alternatives Composition Composition of cryptosystems Encrypting a message multiple times with the same or different ciphers and keys seems to make the cipher stronger, but that's not always the case. The security of the composition can be difficult to analyze. For example, with the one-time pad, the encryption and decryption functions Ek and Dk are the same. The composition Ek ◦ Ek is the identity function! CPSC 367, Lecture 7 4/58 Outline Multiple Encryption Birthday Attack Advanced Encryption Standard Real-World Alternatives Composition Composition within practical cryptosystems Practical symmetric cryptosystems such as DES and AES are built as a composition of simpler systems. Each component offers little security by itself, but when composed, the layers obscure the message to the point that it is difficult for an adversary to recover. The trick is to find ciphers that successfully hide useful information from a would-be attacker when used in concert. CPSC 367, Lecture 7 5/58 Outline Multiple Encryption Birthday Attack Advanced Encryption Standard Real-World Alternatives Composition Double Encryption Double encryption is when a cryptosystem is composed with itself.
    [Show full text]
  • Implementations of Block Cipher SEED on Smartphone Operating Systems
    SECURWARE 2011 : The Fifth International Conference on Emerging Security Information, Systems and Technologies Implementations of Block Cipher SEED on Smartphone Operating Systems HwanJin Lee, DongHoon Shin, and Hyun-Chul Jung Security R&D Team Korea Internet & Security Agency (KISA) Seoul, Korea {lhj79, dhshin, hcjung}@kisa.or.kr Abstract—As more and more people are using smartphones limited power and offers inferior performance compared to a these days, a great deal of important information, such as PC. Therefore, it is difficult to use an open cryptographic personal information and the important documents of library such as OpenSSL, which is designed for the PC corporations among other things, are being saved on environment, in a smartphone. We need to study on the way smartphones. Unlike a PC, people can access another person’s for the effective use of SEED in smartphone. smartphone without great difficulty, and there is a high This paper presents the results of implementing the block possibility of losing one’s smartphone. If smartphone is lost cipher SEED to a smartphone. The results of a comparison without encryption, important information can be exploited. In with open cryptographic libraries (OpenSSL, BouncyCastle) addition, the open cryptographic library for PCs cannot be will also be presented. The SEED is a block cipher used due to the limited performance of the smartphone. This established as an international standard ISO/IEC and the paper introduces the optimization implementation technique for the smartphone OS and the results of using that technique. Korean standard. Section 2 introduces the SEED and open In addition, the results of a speed comparison with the open cryptographic libraries; Section 3 introduces smartphone cryptographic library will be presented.
    [Show full text]
  • Zero Correlation Linear Cryptanalysis on LEA Family Ciphers
    Journal of Communications Vol. 11, No. 7, July 2016 Zero Correlation Linear Cryptanalysis on LEA Family Ciphers Kai Zhang, Jie Guan, and Bin Hu Information Science and Technology Institute, Zhengzhou 450000, China Email: [email protected]; [email protected]; [email protected] Abstract—In recent two years, zero correlation linear Zero correlation linear cryptanalysis was firstly cryptanalysis has shown its great potential in cryptanalysis and proposed by Andrey Bogdanov and Vicent Rijmen in it has proven to be effective against massive ciphers. LEA is a 2011 [2], [3]. Generally speaking, this cryptanalytic block cipher proposed by Deukjo Hong, who is the designer of method can be concluded as “use linear approximation of an ISO standard block cipher - HIGHT. This paper evaluates the probability 1/2 to eliminate the wrong key candidates”. security level on LEA family ciphers against zero correlation linear cryptanalysis. Firstly, we identify some 9-round zero However, in this basic model of zero correlation linear correlation linear hulls for LEA. Accordingly, we propose a cryptanalysis, the data complexity is about half of the full distinguishing attack on all variants of 9-round LEA family code book. The high data complexity greatly limits the ciphers. Then we propose the first zero correlation linear application of this new method. In FSE 2012, multiple cryptanalysis on 13-round LEA-192 and 14-round LEA-256. zero correlation linear cryptanalysis [4] was proposed For 13-round LEA-192, we propose a key recovery attack with which use multiple zero correlation linear approximations time complexity of 2131.30 13-round LEA encryptions, data to reduce the data complexity.
    [Show full text]
  • Multiple New Formulas for Cipher Performance Computing
    International Journal of Network Security, Vol.20, No.4, PP.788-800, July 2018 (DOI: 10.6633/IJNS.201807 20(4).21) 788 Multiple New Formulas for Cipher Performance Computing Youssef Harmouch1, Rachid Elkouch1, Hussain Ben-azza2 (Corresponding author: Youssef Harmouch) Department of Mathematics, Computing and Networks, National Institute of Posts and Telecommunications1 10100, Allal El Fassi Avenue, Rabat, Morocco (Email:[email protected] ) Department of Industrial and Production Engineering, Moulay Ismail University2 National High School of Arts and Trades, Mekns, Morocco (Received Apr. 03, 2017; revised and accepted July 17, 2017) Abstract are not necessarily commensurate properties. For exam- ple, an online newspaper will be primarily interested in Cryptography is a science that focuses on changing the the integrity of their information while a financial stock readable information to unrecognizable and useless data exchange network may define their security as real-time to any unauthorized person. This solution presents the availability and information privacy [14, 23]. This means main core of network security, therefore the risk analysis that, the many facets of the attribute must all be iden- for using a cipher turn out to be an obligation. Until now, tified and adequately addressed. Furthermore, the secu- the only platform for providing each cipher resistance is rity attributes are terms of qualities, thus measuring such the cryptanalysis study. This cryptanalysis can make it quality terms need a unique identification for their inter- hard to compare ciphers because each one is vulnerable to pretations meaning [20, 24]. Besides, the attributes can a different kind of attack that is often very different from be interdependent.
    [Show full text]
  • Using Address Independent Seed Encryption and Bonsai Merkle Trees to Make Secure Processors OS- and Performance-Friendly ∗
    Using Address Independent Seed Encryption and Bonsai Merkle Trees to Make Secure Processors OS- and Performance-Friendly ∗ Brian Rogers, Siddhartha Chhabra, Yan Solihin Milos Prvulovic Dept. of Electrical and Computer Engineering College of Computing North Carolina State University Georgia Institute of Technology {bmrogers, schhabr, solihin}@ncsu.edu [email protected] Abstract and feasible threat is physical or hardware attacks which involve placing a bus analyzer that snoops data communicated between the In today’s digital world, computer security issues have become processor chip and other chips [7, 8]. Although physical attacks increasingly important. In particular, researchers have proposed may be more difficult to perform than software-based attacks, they designs for secure processors which utilize hardware-based mem- are very powerful as they can bypass any software security protec- ory encryption and integrity verification to protect the privacy and tion employed in the system. The proliferation of mod-chips that integrity of computation even from sophisticated physical attacks. bypass Digital Rights Management protection in game systems has However, currently proposed schemes remain hampered by prob- demonstrated that given sufficient financial payoffs, physical attacks lems that make them impractical for use in today’s computer sys- are very realistic threats. tems: lack of virtual memory and Inter-Process Communication Recognizing these threats, computer architecture researchers support as well as excessive storage and performance overheads. have recently proposed various types of secure processor architec- In this paper, we propose 1) Address Independent Seed Encryption tures [4, 5, 13, 14, 16, 17, 18, 19, 20, 22, 23, 24, 25, 26]. Secure pro- (AISE), a counter-mode based memory encryption scheme using a cessors assume that off-chip communication is vulnerable to attack novel seed composition, and 2) Bonsai Merkle Trees (BMT), a novel and that the chip boundary provides a natural security boundary.
    [Show full text]
  • Performance and Energy Efficiency of Block Ciphers in Personal Digital Assistants
    Performance and Energy Efficiency of Block Ciphers in Personal Digital Assistants Creighton T. R. Hager, Scott F. Midkiff, Jung-Min Park, Thomas L. Martin Bradley Department of Electrical and Computer Engineering Virginia Polytechnic Institute and State University Blacksburg, Virginia 24061 USA {chager, midkiff, jungmin, tlmartin} @ vt.edu Abstract algorithms may consume more energy and drain the PDA battery faster than using less secure algorithms. Due to Encryption algorithms can be used to help secure the processing requirements and the limited computing wireless communications, but securing data also power in many PDAs, using strong cryptographic consumes resources. The goal of this research is to algorithms may also significantly increase the delay provide users or system developers of personal digital between data transmissions. Thus, users and, perhaps assistants and applications with the associated time and more importantly, software and system designers need to energy costs of using specific encryption algorithms. be aware of the benefits and costs of using various Four block ciphers (RC2, Blowfish, XTEA, and AES) were encryption algorithms. considered. The experiments included encryption and This research answers questions regarding energy decryption tasks with different cipher and file size consumption and execution time for various encryption combinations. The resource impact of the block ciphers algorithms executing on a PDA platform with the goal of were evaluated using the latency, throughput, energy- helping software and system developers design more latency product, and throughput/energy ratio metrics. effective applications and systems and of allowing end We found that RC2 encrypts faster and uses less users to better utilize the capabilities of PDA devices.
    [Show full text]
  • FIPS 140-2 Non-Proprietary Security Policy Oracle Linux 7 NSS
    FIPS 140-2 Non-Proprietary Security Policy Oracle Linux 7 NSS Cryptographic Module FIPS 140-2 Level 1 Validation Software Version: R7-4.0.0 Date: January 22nd, 2020 Document Version 2.3 © Oracle Corporation This document may be reproduced whole and intact including the Copyright notice. Title: Oracle Linux 7 NSS Cryptographic Module Security Policy Date: January 22nd, 2020 Author: Oracle Security Evaluations – Global Product Security Contributing Authors: Oracle Linux Engineering Oracle Corporation World Headquarters 500 Oracle Parkway Redwood Shores, CA 94065 U.S.A. Worldwide Inquiries: Phone: +1.650.506.7000 Fax: +1.650.506.7200 oracle.com Copyright © 2020, Oracle and/or its affiliates. All rights reserved. This document is provided for information purposes only and the contents hereof are subject to change without notice. This document is not warranted to be error-free, nor subject to any other warranties or conditions, whether expressed orally or implied in law, including implied warranties and conditions of merchantability or fitness for a particular purpose. Oracle specifically disclaim any liability with respect to this document and no contractual obligations are formed either directly or indirectly by this document. This document may reproduced or distributed whole and intact including this copyright notice. Oracle and Java are registered trademarks of Oracle and/or its affiliates. Other names may be trademarks of their respective owners. Oracle Linux 7 NSS Cryptographic Module Security Policy i TABLE OF CONTENTS Section Title
    [Show full text]
  • Internet Engineering Task Force (IETF) S. Kanno Request for Comments: 6367 NTT Software Corporation Category: Informational M
    Internet Engineering Task Force (IETF) S. Kanno Request for Comments: 6367 NTT Software Corporation Category: Informational M. Kanda ISSN: 2070-1721 NTT September 2011 Addition of the Camellia Cipher Suites to Transport Layer Security (TLS) Abstract This document specifies forty-two cipher suites for the Transport Security Layer (TLS) protocol to support the Camellia encryption algorithm as a block cipher. Status of This Memo This document is not an Internet Standards Track specification; it is published for informational purposes. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Not all documents approved by the IESG are a candidate for any level of Internet Standard; see Section 2 of RFC 5741. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc6367. Copyright Notice Copyright (c) 2011 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
    [Show full text]
  • Preliminary Analysis: SEED’S First Year
    SEED Findings Summary stocktondemonstration.org Preliminary Analysis: SEED’s First Year AUTHORS: CONTRIBUTING RESEARCHERS: Dr. Stacia West, Mina Addo, Mae Carlson, Dr. Amy Castro Baker, Conway Homes Residents Council, Sukhi Samra, Pandora Crowder, Meagan Cusack, Stacy Elliott, Erin Coltrera Daniel Horn, Jenna Steckel, Tooma Zaghloul Preliminary Analysis: SEED's First Year Executive Summary “ Poverty is the biggest issue. Everything we deal with stems from that. There’s so many people working incredibly hard, and if life happens, there’s no bottom. “ —Michael D. Tubbs The Stockton Economic Empowerment Key Findings Include: Demonstration, or SEED, was the nation’s • Guaranteed income reduced income volatility, first mayor-led guaranteed income initiative. or the month-to-month income fluctuations Launched in February 2019 by former Mayor that households face. Michael D. Tubbs, SEED gave 125 Stocktonians $500 per month for 24 months. The cash was • Unconditional cash enabled recipients unconditional, with no strings attached and no to find full-time employment. work requirements. • Recipients of guaranteed income were This Randomized Control Trial (RCT) pilot is being healthier, showing less depression and anxiety evaluated by a team of independent researchers, and enhanced wellbeing. Dr. Stacia West of the University of Tennessee • The guaranteed income alleviated financial and Dr. Amy Castro Baker of the University of scarcity creating new opportunities for Pennsylvania, and funded by the Evidence for self-determination, choice, goal-setting, Action Program at the Robert Wood Johnson and risk-taking. Foundation. SEED sought to confront, address, and humanize Our primary research questions are the following: some of the most pressing and pernicious How does guaranteed income impact problems our country faces: inequality, income income volatility? How do changes in income volatility, and poverty.
    [Show full text]
  • Comparative Study of Cryptographic Encryption Algorithms
    IOSR Journal of Electronics and Communication Engineering (IOSR-JECE) e-ISSN: 2278-2834,p- ISSN: 2278-8735.Volume 12, Issue 3, Ver. II (May - June 2017), PP 66-71 www.iosrjournals.org Comparative Study of Cryptographic Encryption Algorithms Chaitra B1, Kiran Kumar V.G.1, Shantharama Rai C2 1(Electronics & Communication Engineering, Sahyadri College of Engineering& Management, India) 1(Associate Professor Electronics & Communication Engineering, Sahyadri College of Engineering & Management, India) 2(Principal,, AJ Institute of Engineering &Technology, Mangaluru, India) Abstract: Protection of the network to enhance the safety of the information is great challenge in cryptography. With the developments in the cryptography lightweight cryptography has large space towards security by its simplicity in the implementations. For majority of applications PRESENT and TEA are excellent and preferred choices. However PRESENT is suitable for low constrained devices like RFID tags and sensor network. In this paper we describe ultra-lightweight cryptographic algorithms in detail. Both efficiency and security of information are important while designing and implementation considering security, cost and performance. The efficiency of PRESENT and TEA are higher as they have ability to resist cryptographic attacks and also due to their adequate security. In this paper the performance analysis of PRESENT and Tea are described. I. Introduction In digital era secrecy of the information plays important role in cryptography. Cryptography is the integral part of communication organization. PRESENT is newly introduced lightweight cryptographic algorithm. It is mainly designed for devices which have extremely low constrained resources in terms of area power and time. If we relate the performance analysis with other PRESENT is better block ciphers.
    [Show full text]