Public-Key Cryptography
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
A Secure Authentication System- Using Enhanced One Time Pad Technique
IJCSNS International Journal of Computer Science and Network Security, VOL.11 No.2, February 2011 11 A Secure Authentication System- Using Enhanced One Time Pad Technique Raman Kumar1, Roma Jindal 2, Abhinav Gupta3, Sagar Bhalla4 and Harshit Arora 5 1,2,3,4,5 Department of Computer Science and Engineering, 1,2,3,4,5 D A V Institute of Engineering and Technology, Jalandhar, Punjab, India. Summary the various weaknesses associated with a password have With the upcoming technologies available for hacking, there is a come to surface. It is always possible for people other than need to provide users with a secure environment that protect their the authenticated user to posses its knowledge at the same resources against unauthorized access by enforcing control time. Password thefts can and do happen on a regular basis, mechanisms. To counteract the increasing threat, enhanced one so there is a need to protect them. Rather than using some time pad technique has been introduced. It generally random set of alphabets and special characters as the encapsulates the enhanced one time pad based protocol and provides client a completely unique and secured authentication passwords we need something new and something tool to work on. This paper however proposes a hypothesis unconventional to ensure safety. At the same time we need regarding the use of enhanced one time pad based protocol and is to make sure that it is easy to be remembered by you as a comprehensive study on the subject of using enhanced one time well as difficult enough to be hacked by someone else. -
A Comparitive Study of Asymmetric Key Cryptography
Vol-5 Issue-3 2019 IJARIIE-ISSN(O)-2395-4396 A COMPARITIVE STUDY OF ASYMMETRIC KEY CRYPTOGRAPHY Dr. Prashant P. Pittalia Associate Professor, Department of Computer Science, Gujarat, India ABSTRACT Cryptography is use to secure the computer networks. Cryptography converts the plain text into cipher text such a way that it is impossible for intruders to read and understand the content. Asymmetric key cryptography is based on the public key and private key concepts to support the confidentiality and authentication services in computer networks. This paper describes how confidentiality and authentication service provides by asymmetric key algorithms. In this paper the discussion and comparison of a asymmetric key algorithms like RSA, Diffie-Hellman, ElGamal and ECC. Keyword: - RSA, Authentication, Public key, Private Key, Confidentiality 1. INTRODUCTION Today in global village the internet security is the challenging aspect and cryptography is used for it. Cryptography is the mathematical techniques of information security. It supports confidentiality, privacy, and data integrity and entity authentication. Cryptography systems classified into two main categories symmetric-key cryptography that use a symmetric key used by both sender and recipient and a public-key cryptography that use two keys, a public key known to everyone in the network and a private key that is used by only the recipient of the messages. Symmetric algorithms use the same secret key for both encryption of plaintext and decryption of cipher text. The keys may be same or there may be an easy transformation to go between the two keys. The key is shared between the two parties (sender and receiver) who want to communicate. -
Cryptography in Modern World
Cryptography in Modern World Julius O. Olwenyi, Aby Tino Thomas, Ayad Barsoum* St. Mary’s University, San Antonio, TX (USA) Emails: [email protected], [email protected], [email protected] Abstract — Cryptography and Encryption have been where a letter in plaintext is simply shifted 3 places down used for secure communication. In the modern world, the alphabet [4,5]. cryptography is a very important tool for protecting information in computer systems. With the invention ABCDEFGHIJKLMNOPQRSTUVWXYZ of the World Wide Web or Internet, computer systems are highly interconnected and accessible from DEFGHIJKLMNOPQRSTUVWXYZABC any part of the world. As more systems get interconnected, more threat actors try to gain access The ciphertext of the plaintext “CRYPTOGRAPHY” will to critical information stored on the network. It is the be “FUBSWRJUASLB” in a Caesar cipher. responsibility of data owners or organizations to keep More recent derivative of Caesar cipher is Rot13 this data securely and encryption is the main tool used which shifts 13 places down the alphabet instead of 3. to secure information. In this paper, we will focus on Rot13 was not all about data protection but it was used on different techniques and its modern application of online forums where members could share inappropriate cryptography. language or nasty jokes without necessarily being Keywords: Cryptography, Encryption, Decryption, Data offensive as it will take those interested in those “jokes’ security, Hybrid Encryption to shift characters 13 spaces to read the message and if not interested you do not need to go through the hassle of converting the cipher. I. INTRODUCTION In the 16th century, the French cryptographer Back in the days, cryptography was not all about Blaise de Vigenere [4,5], developed the first hiding messages or secret communication, but in ancient polyalphabetic substitution basically based on Caesar Egypt, where it began; it was carved into the walls of cipher, but more difficult to crack the cipher text. -
A Practical Implementation of a One-Time Pad Cryptosystem
Jeff Connelly CPE 456 June 11, 2008 A Practical Implementation of a One-time Pad Cryptosystem 0.1 Abstract How to securely transmit messages between two people has been a problem for centuries. The first ciphers of antiquity used laughably short keys and insecure algorithms easily broken with today’s computational power. This pattern has repeated throughout history, until the invention of the one-time pad in 1917, the world’s first provably unbreakable cryptosystem. However, the public generally does not use the one-time pad for encrypting their communication, despite the assurance of confidentiality, because of practical reasons. This paper presents an implementation of a practical one-time pad cryptosystem for use between two trusted individuals, that have met previously but wish to securely communicate over email after their departure. The system includes the generation of a one-time pad using a custom-built hardware TRNG as well as software to easily send and receive encrypted messages over email. This implementation combines guaranteed confidentiality with practicality. All of the work discussed here is available at http://imotp.sourceforge.net/. 1 Contents 0.1 Abstract.......................................... 1 1 Introduction 3 2 Implementation 3 2.1 RelatedWork....................................... 3 2.2 Description ........................................ 3 3 Generating Randomness 4 3.1 Inadequacy of Pseudo-random Number Generation . 4 3.2 TrulyRandomData .................................... 5 4 Software 6 4.1 Acquiring Audio . 6 4.1.1 Interference..................................... 6 4.2 MeasuringEntropy................................... 6 4.3 EntropyExtraction................................ ..... 7 4.3.1 De-skewing ..................................... 7 4.3.2 Mixing........................................ 7 5 Exchanging Pads 8 5.1 Merkle Channels . 8 5.2 Local Pad Security . -
Historical Ciphers • A
ECE 646 - Lecture 6 Required Reading • W. Stallings, Cryptography and Network Security, Chapter 2, Classical Encryption Techniques Historical Ciphers • A. Menezes et al., Handbook of Applied Cryptography, Chapter 7.3 Classical ciphers and historical development Why (not) to study historical ciphers? Secret Writing AGAINST FOR Steganography Cryptography (hidden messages) (encrypted messages) Not similar to Basic components became modern ciphers a part of modern ciphers Under special circumstances modern ciphers can be Substitution Transposition Long abandoned Ciphers reduced to historical ciphers Transformations (change the order Influence on world events of letters) Codes Substitution The only ciphers you Ciphers can break! (replace words) (replace letters) Selected world events affected by cryptology Mary, Queen of Scots 1586 - trial of Mary Queen of Scots - substitution cipher • Scottish Queen, a cousin of Elisabeth I of England • Forced to flee Scotland by uprising against 1917 - Zimmermann telegram, America enters World War I her and her husband • Treated as a candidate to the throne of England by many British Catholics unhappy about 1939-1945 Battle of England, Battle of Atlantic, D-day - a reign of Elisabeth I, a Protestant ENIGMA machine cipher • Imprisoned by Elisabeth for 19 years • Involved in several plots to assassinate Elisabeth 1944 – world’s first computer, Colossus - • Put on trial for treason by a court of about German Lorenz machine cipher 40 noblemen, including Catholics, after being implicated in the Babington Plot by her own 1950s – operation Venona – breaking ciphers of soviet spies letters sent from prison to her co-conspirators stealing secrets of the U.S. atomic bomb in the encrypted form – one-time pad 1 Mary, Queen of Scots – cont. -
Secure Communications One Time Pad Cipher
Cipher Machines & Cryptology © 2010 – D. Rijmenants http://users.telenet.be/d.rijmenants THE COMPLETE GUIDE TO SECURE COMMUNICATIONS WITH THE ONE TIME PAD CIPHER DIRK RIJMENANTS Abstract : This paper provides standard instructions on how to protect short text messages with one-time pad encryption. The encryption is performed with nothing more than a pencil and paper, but provides absolute message security. If properly applied, it is mathematically impossible for any eavesdropper to decrypt or break the message without the proper key. Keywords : cryptography, one-time pad, encryption, message security, conversion table, steganography, codebook, message verification code, covert communications, Jargon code, Morse cut numbers. version 012-2011 1 Contents Section Page I. Introduction 2 II. The One-time Pad 3 III. Message Preparation 4 IV. Encryption 5 V. Decryption 6 VI. The Optional Codebook 7 VII. Security Rules and Advice 8 VIII. Appendices 17 I. Introduction One-time pad encryption is a basic yet solid method to protect short text messages. This paper explains how to use one-time pads, how to set up secure one-time pad communications and how to deal with its various security issues. It is easy to learn to work with one-time pads, the system is transparent, and you do not need special equipment or any knowledge about cryptographic techniques or math. If properly used, the system provides truly unbreakable encryption and it will be impossible for any eavesdropper to decrypt or break one-time pad encrypted message by any type of cryptanalytic attack without the proper key, even with infinite computational power (see section VII.b) However, to ensure the security of the message, it is of paramount importance to carefully read and strictly follow the security rules and advice (see section VII). -
Committee on National Security Systems (CNSS) Glossary
Committee on National Security Systems CNSSI No. 4009 April 6, 2015 Committee on National Security Systems (CNSS) Glossary THIS DOCUMENT PRESCRIBES MINIMUM STANDARDS YOUR DEPARTMENT OR AGENCY MAY REQUIRE FURTHER IMPLEMENTATION 1 National Manager FOREWORD 1. The Committee on National Security Systems (CNSS) Glossary Working Group convened to review and update the Committee on National Security Systems (CNSS) Glossary, Committee on National Security Systems Instruction (CNSSI) No. 4009, dated April 2010. This revision of CNSSI No. 4009 incorporates many new terms submitted by the CNSS Membership. Most of the terms from the 2010 version of the Glossary remain, but a number of terms have updated definitions in order to remove inconsistencies among the communities. 2. The Glossary Working Group set several overall objectives for itself in producing this version: . Use authoritative sources for definitions of terms. It is preferred that definitions originate from current authoritative sources, as this demonstrates both that the term is in active use and that the definition has been vetted by subject matter experts. Listing sources for terms also provides context and a reference for additional information. The glossary still contains terms where sources are not specified. For these terms, definitions will be considered organic. The majority of unsourced terms are from the CNSSI No. 4009 (2010) version, although some are newly introduced. These new terms are primarily emerging terms judged to be valuable to include in the glossary, but for whatever reason have not yet been defined in a published authoritative source. Continue to resolve differences between the definitions of terms used by the Department of Defense (DoD), Intelligence Community (IC), and Civil Agencies (e.g. -
Secure Communications One Time Pad Cipher
Cipher Machines & Cryptology Ed. 7.4 – Jan 22, 2016 © 2009 - 2016 D. Rijmenants http://users.telenet.be/d.rijmenants THE COMPLETE GUIDE TO SECURE COMMUNICATIONS WITH THE ONE TIME PAD CIPHER DIRK RIJMENANTS Abstract : This paper provides standard instructions on how to protect short text messages with one-time pad encryption. The encryption is performed with nothing more than a pencil and paper, but provides absolute message security. If properly applied, it is mathematically impossible for any eavesdropper to decrypt or break the message without the proper key. Keywords : cryptography, one-time pad, encryption, message security, conversion table, steganography, codebook, covert communications, Morse cut numbers. 1 Contents 1. Introduction………………………………. 2 2. The One-time Pad………………………. 3 3. Message Preparation…………………… 4 4. Encryption………………………………... 5 5. Decryption………………………………... 6 6. The Optional Codebook………………… 7 7. Security Rules and Advice……………… 8 8. Is One-time Pad Really Unbreakable…. 16 9. Legal Issues and Personal Security…... 18 10. Appendices………………………………. 19 1. Introduction One-time pad encryption is a basic yet solid method to protect short text messages. This paper explains how to use one-time pads, how to set up secure one-time pad communications and how to deal with its various security issues. Working with one-time pads is easy to learn. The system is transparent and you do not need a computer, special equipment or any knowledge about cryptographic techniques or mathematics. One-time pad encryption is an equation with two unknowns, which is mathematically unsolvable. The system therefore provides truly unbreakable encryption when properly used. It will never be possible to decipher one-time pad encrypted data without having the proper key, regardless any existing or future cryptanalytic attack or technology, infinite computational power or infinite time. -
A Brief History of Cryptography
University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Supervised Undergraduate Student Research Chancellor’s Honors Program Projects and Creative Work Spring 5-2000 A Brief History of Cryptography William August Kotas University of Tennessee - Knoxville Follow this and additional works at: https://trace.tennessee.edu/utk_chanhonoproj Recommended Citation Kotas, William August, "A Brief History of Cryptography" (2000). Chancellor’s Honors Program Projects. https://trace.tennessee.edu/utk_chanhonoproj/398 This is brought to you for free and open access by the Supervised Undergraduate Student Research and Creative Work at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Chancellor’s Honors Program Projects by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. Appendix D- UNIVERSITY HONORS PROGRAM SENIOR PROJECT - APPROVAL Name: __ l1~Ui~-~-- A~5-~~± ---l(cl~-~ ---------------------- ColI e g e: _l~.:i~_~__ ~.:--...!j:.~~~ __ 0 epa r t men t: _ {~~.f_':.~::__ ~,:::..!._~_~_s,_ Fa c u 1ty Me n tor: ____Q-' _·__ ~~~~s..0_~_L __ D_~_ ~_o_~t _______________ _ PRO JE CT TITL E: ____~ __ ~c ~ :.f __ l1L~_ ~_I_x __ 9_( __( ~~- ~.t~~-.r--~~ - I have reviewed this completed senior honors thesis "\lith this student and certifv that it is a project commensurate with honors level undergraduate research in this field. Signed ~u:t2~--------------- , Facultv .'vfentor Date: --d~I-~--Q-------- Comments (Optional): A BRIEF HISTORY OF CRYPTOGRAPHY Prepared by William A. Kotas For Honors Students at the University of Tennessee May 5, 2000 ABSTRACT This paper presents an abbreviated history of cryptography. -
CS355: Cryptography
Cristina Nita-Rotaru CS355: Cryptography Lecture 5: One–time pad. One-time pad } Extend Vigenère cipher so that the key is as long as the plaintext } No repeat, cannot be broken by finding key length + frequency analysis } Key is a random string that is at least as long as the plaintext } Encryption is similar to Vigenère 2 Cristina Nita-Rotaru History of One-time pad } 1882 - First described by Frank Miller } 1917 - Re-invented by Gilbert Vernam; one time pad also known as the Vernam cipher } 1919 - Patented by Vernam } Joseph Mauborgne recognized that having the key totally random increased security } 1949 – showed the One-time pad had perfect secrecy, Shannon 3 Cristina Nita-Rotaru Gilbert Sandford Joseph Mauborgne Vernam (1890 - 1960), (1881-1971) was a was AT&T Bell Labs Major General in the Claude Elwood Shannon engineer" United States Army" (1916 - 2001), American electronic engineer and mathematician, was "the father of information theory " 4 Cristina Nita-Rotaru One-time pad: encryption and decryption Key is chosen randomly Plaintext X = (x1 x2 … xn) Key K = (k1 k2 … kn) Ciphertext Y = (y1 y2 … yn) ek(X) = (x1+k1 x2+k2 … xn+kn) mod m dk(Y) = (y1- k1 y2-k2 … yn-kn) mod m 5 Cristina Nita-Rotaru Binary version of One-time pad Plaintext space = Ciphtertext space = Keyspace = {0,1}n Key is chosen randomly For example: }! Plaintext is 11011011 }! Key is 01101001 }! Then ciphertext is 10110010 6 Cristina Nita-Rotaru Bit operators }! Bit AND 0 ∧ 0 = 0 0 ∧ 1 = 0 1 ∧ 0 = 0 1 ∧ 1 = 1 }! Bit OR 0 ∨ 0 = 0 0 ∨ 1 = 1 1 ∨ 0 = 1 1 ∨ 1 = 1 }! Addition mod 2 (also known as Bit XOR) 0 ⊕ 0 = 0 0 ⊕ 1 = 1 1 ⊕ 0 = 1 1 ⊕ 1 = 0 7 Cristina Nita-Rotaru Security of One-time pad }! Intuitively, it is secure … }! The key is random, so the ciphertext is completely random 8 Cristina Nita-Rotaru Information-theoretic security } Basic Idea: Ciphertext should provide no “information” about plaintext } We also say such a scheme has perfect secrecy. -
AUTUMN 2012 8/10/12 13:17 Page 1
sip AUTUMN 2012 8/10/12 13:17 Page 1 SCIENCE IN PARLIAMENT A proton collides with a proton The Higgs boson appears at last sip AUTUMN 2012 The Journal of the Parliamentary and Scientific Committee www.scienceinparliament.org.uk sip AUTUMN 2012 8/10/12 13:17 Page 2 Physics for All Science and engineering students are important for the future of the UK IOP wants to see more people studying physics www.iop.org / 35 $' 3$5/, $ LQGG sip AUTUMN 2012 8/10/12 13:17 Page 3 Last years's winter of discontent was indeed made SCIENCE IN PARLIAMENT glorious summer by several sons and daughters of York. So many medals in the Olympics were won by scions of Yorkshire that the county claimed tenth place in the medals table, something hard to accept on my side of the Pennines! As well as being fantastic athletic performances the Olympics and Paralympics were stunning demonstrations of the efficiency of UK engineering, and sip the imagination of British science. The Journal of the Parliamentary and Scientific Surely we have good reason to be all eagerly awaiting Andrew Miller MP Committee. Chairman, Parliamentary The Committee is an Associate Parliamentary the announcements from Stockholm of this year's Nobel and Scientific Group of members of both Houses of Prizes? Surely the Higgs boson will be recognised? John Committee Parliament and British members of the European Parliament, representatives of Ellis recently eloquently described the "legacy" of the scientific and technical institutions, industrial hadron collider and we would be missing an important organisations and universities. -
Expertise As an Object: an Ontological Study of Cryptology Research in the United Kingdom from 1970 to 2000
UNIVERSITY OF SURREY Expertise as an Object: An Ontological Study of Cryptology Research in the United Kingdom from 1970 to 2000 by Richard Fletcher Submitted for the degree of Doctor of Philosophy Faculty of Arts and Human Sciences Department of Sociology Supervisors: Dr Christine Hine and Dr Nicola Green ©Richard Fletcher Words: 95,698 Declaration of Authorship This thesis and the work to which it refers are the results of my own efforts. Any ideas, data, images or text resulting from the work of others (whether published or unpublished) are fully identified as such within the work and attributed to their originator in the text, bibliography or in footnotes. This thesis has not been submitted in whole or in part for any other academic degree or professional qualification. I agree that the University has the right to submit my work to the plagiarism detection service TurnitinUK for originality checks. Whether or not drafts have been so-assessed, the University reserves the right to require an electronic version of the final document (as submitted) for assessment as above. Signature: Date: i \Quis custodiet ipsos custodes?" Juvenal (Satire VI, lines 347-8) Abstract Recent research carried out under the `third wave of science studies' has produced robust categories of expertise, and has developed normative ideas about how it should be used during controversies over technological decision-making. Though separate in the literature, third wave ideas about contributory expertise appear to be compatible with the recent `turn to ontology'. Both sets of ideas focus on what it is that practices are able to produce, and consider the results of those practices to be real.