public key cryptography a practical public key
play

Public key cryptography: a practical Public key cryptography: a - PowerPoint PPT Presentation

Nov 19, 2023 •561 likes •996 views

Public key cryptography: a practical Public key cryptography: a practical approach approach Israel Herraiz <isra@herraiz.org> <israel.herraiz@upm.es> KeyID FE0A7AF3 Fingerprint D0DA E915 BFDD E5CD 8BA0 B159 7E97 2ACB FE0A 7AF3

  1. Public key cryptography: a practical Public key cryptography: a practical approach approach Israel Herraiz <isra@herraiz.org> <israel.herraiz@upm.es> KeyID FE0A7AF3 Fingerprint D0DA E915 BFDD E5CD 8BA0 B159 7E97 2ACB FE0A 7AF3 Slides and additional info at http://mat.caminos.upm.es/~iht/pkc/ 1 http://herraiz.org

  2. Privacy in electronic communicatios Privacy in electronic communicatios Can we ensure privacy in electronic communications? 2 http://herraiz.org

  3. Reaching Google Reaching Google 1 10.8.0.1 ( 10.8.0.1 ) 1 10.8.0.1 ( 10.8.0.1 ) 2 192.168.1.1 ( 192.168.1.1 ) 2 192.168.1.1 ( 192.168.1.1 ) 3 62.81.125.179.static.user.ono.com ( 62.81.125.179 ) 3 62.81.125.179.static.user.ono.com ( 62.81.125.179 ) 4 10.115.49.217 ( 10.115.49.217 ) 4 10.115.49.217 ( 10.115.49.217 ) 5 10.127.151.49 ( 10.127.151.49 ) 5 10.127.151.49 ( 10.127.151.49 ) 6 10.127.10.137 ( 10.127.10.137 ) 6 10.127.10.137 ( 10.127.10.137 ) 7 10.127.10.133 ( 10.127.10.133 ) 7 10.127.10.133 ( 10.127.10.133 ) 8 10.127.3.82 ( 10.127.3.82 ) 8 10.127.3.82 ( 10.127.3.82 ) 9 213.242.71.21 ( 213.242.71.21 ) 9 213.242.71.21 ( 213.242.71.21 ) 10 ae-5-5.ebr1.Paris1.Level3.net ( 4.69.141.42 ) 10 ae-5-5.ebr1.Paris1.Level3.net ( 4.69.141.42 ) 11 ae-45-45.ebr1.London1.Level3.net ( 4.69.143.101 ) 11 ae-45-45.ebr1.London1.Level3.net ( 4.69.143.101 ) 12 ae-1-51.edge3.London1.Level3.net ( 4.69.139.73 ) 12 ae-1-51.edge3.London1.Level3.net ( 4.69.139.73 ) 13 unknown.Level3.net ( 212.113.15.186 ) 13 unknown.Level3.net ( 212.113.15.186 ) 14 209.85.255.78 ( 209.85.255.78 ) 14 209.85.255.78 ( 209.85.255.78 ) 15 66.249.95.173 ( 66.249.95.173 ) 15 66.249.95.173 ( 66.249.95.173 ) 16 216.239.49.45 ( 216.239.49.45 ) 16 216.239.49.45 ( 216.239.49.45 ) 17 * * * 17 * * * 18 ww-in-f147.1e100.net ( 209.85.229.147 ) 18 ww-in-f147.1e100.net ( 209.85.229.147 ) 3 http://herraiz.org

  4. Reaching Google Reaching Google 1 10.8.0.1 ( 10.8.0.1 ) 1 10.8.0.1 ( 10.8.0.1 ) Getafe 2 192.168.1.1 ( 192.168.1.1 ) 2 192.168.1.1 ( 192.168.1.1 ) 3 62.81.125.179.static.user.ono.com ( 62.81.125.179 ) 3 62.81.125.179.static.user.ono.com ( 62.81.125.179 ) 4 10.115.49.217 ( 10.115.49.217 ) 4 10.115.49.217 ( 10.115.49.217 ) 5 10.127.151.49 ( 10.127.151.49 ) 5 10.127.151.49 ( 10.127.151.49 ) Barcelona 6 10.127.10.137 ( 10.127.10.137 ) 6 10.127.10.137 ( 10.127.10.137 ) 7 10.127.10.133 ( 10.127.10.133 ) 7 10.127.10.133 ( 10.127.10.133 ) 8 10.127.3.82 ( 10.127.3.82 ) 8 10.127.3.82 ( 10.127.3.82 ) Minneapolis 9 213.242.71.21 ( 213.242.71.21 ) 9 213.242.71.21 ( 213.242.71.21 ) Paris 10 ae-5-5.ebr1.Paris1.Level3.net ( 4.69.141.42 ) 10 ae-5-5.ebr1.Paris1.Level3.net ( 4.69.141.42 ) 11 ae-45-45.ebr1.London1.Level3.net ( 4.69.143.101 ) 11 ae-45-45.ebr1.London1.Level3.net ( 4.69.143.101 ) 12 ae-1-51.edge3.London1.Level3.net ( 4.69.139.73 ) 12 ae-1-51.edge3.London1.Level3.net ( 4.69.139.73 ) London 13 unknown.Level3.net ( 212.113.15.186 ) 13 unknown.Level3.net ( 212.113.15.186 ) Atlanta 14 209.85.255.78 ( 209.85.255.78 ) 14 209.85.255.78 ( 209.85.255.78 ) 15 66.249.95.173 ( 66.249.95.173 ) 15 66.249.95.173 ( 66.249.95.173 ) New York 16 216.239.49.45 ( 216.239.49.45 ) 16 216.239.49.45 ( 216.239.49.45 ) Los Angeles 17 * * * 17 * * * 18 ww-in-f147.1e100.net ( 209.85.229.147 ) 18 ww-in-f147.1e100.net ( 209.85.229.147 ) Atlanta 4 http://herraiz.org

  5. Hops while attempting to reach Hops while attempting to reach Google Google 5 http://herraiz.org

  6. Is it that bad? Is it that bad? What kind of private Information can be captured? 6 http://herraiz.org

  7. Non-cyphered information Non-cyphered information ● Geolocalization ● Using your IP address ● Web browser and operating system ● Any info written in a form ● Including passwords ● Cookies ● Have a look and take care – http://www.youtube.com/watch?v=yyLdxO6xvh8 – http://www.youtube.com/watch?v=1FgKL2ywrX0 7 http://herraiz.org

  8. Is it important? Is it important? ● Strong PK crypto illegal in France up to 2004 ● PK implementations in software considered weapons in the US ● Software export restrictions in EU and US http://en.wikipedia.org/wiki/Cryptography_law http://en.wikipedia.org/wiki/Key_disclosure_law http://en.wikipedia.org/wiki/Phil_Zimmermann 8 http://en.wikipedia.org/wiki/Export_of_cryptography_in_the_United_States#History http://herraiz.org

  9. Solution Enforce cyphering using public key cryptography 9 http://herraiz.org

  10. Cryptography Cryptography ● Traditionally, cyphering was done using a password and an algorithm ● Symmetric approach ● Password shared by both peers ● Public key cryptography ● Insecure channel ● Private and secure communication without any previous physical contact 10 http://herraiz.org

  11. Public key cryptography (PKP) Public key cryptography (PKP) Pub Pri Pub Pri 11 http://herraiz.org

  12. Public key cryptography Public key cryptography Pub Pri Pub Pri Keyserver Pub Pub 12 http://herraiz.org

  13. Criptografía de clave pública Criptografía de clave pública Hi there! Pub Pri Pub Pri Keyserver Pub Pub 13 http://herraiz.org

  14. Public key cryptography Public key cryptography Pub 0F231A5 Pub Pri Pub Pri Keyserver Pub Pub 14 http://herraiz.org

  15. Public key cryptography Public key cryptography Pub 0F231A5 Pub Pri Pub Pri Keyserver Pub Pub 15 http://herraiz.org

  16. Public key cryptography Public key cryptography Hi there! Pub Pri Pub Pri Keyserver Pub Pub 16 http://herraiz.org

  17. How does it work? How does it work? ● PKP Algorithms ● Prime number factorization ● From a mathematical point of view, all messages can be decrypted ● From a computational point of view, decrypting a message without the private key takes too long – Key length is a crucial property 17 http://herraiz.org

  18. Public key sample Public key sample -----BEGIN PGP PUBLIC KEY BLOCK----- Version: GnuPG v2.0.19 (GNU/Linux) JeP5F/eRS9G8EE1fObRRW6mRf+bGSeluFEMiOi3UB/5P0GBx8iM0QIjezR0R+2n8 bMjuJmWHTjvEeplnx9iual4J4BT/9FznFs7o4tFVVfYBacFrhWjQyAf2xoP3gyn3 5OlV55VHVB+oidXUVNSNHZbXwrd1sH42x7x8o17PDFJrWjiq4kAb2EfSOIuSS6na K9Y06bqh3yRbVtRdZOuCLcY8QJwt/mx//uQqG6NuSvYhx1QyC6g==XuDESOIuSSa mQINBEtUTeQBEACejdGQhscmsDXM7xG2/ZYFpMQg/GmPlJ85uJJUkLr2T+5Rw8Xv VfZjNZkMwsq94BGFrBxu477tKhQ5wiUBBz/jJ01a39Wrazgp21fvEon2T0Vay45t 2BYbU4AF815UL6o74YlW5SLdAofwylZS8pX4CKjGAB0T+fDiwkAepQl45nzX0ulv -----END PGP PUBLIC KEY BLOCK----- 18 http://herraiz.org

  19. Private key sample Private key sample -----BEGIN PGP PRIVATE KEY BLOCK----- Version: GnuPG v2.0.19 (GNU/Linux) mQINBEtUTeQBEACejdGQhscmsDXM7xG2/ZYFpMQg/GmPlJ85uJJUkLr2T+5Rw8Xv JeP5F/eRS9G8EE1fObRRW6mRf+bGSeluFEMiOi3UB/5P0GBx8iM0QIjezR0R+2n8 VfZjNZkMwsq94BGFrBxu477tKhQ5wiUBBz/jJ01a39Wrazgp21fvEon2T0Vay45t 2BYbU4AF815UL6o74YlW5SLdAofwylZS8pX4CKjGAB0T+fDiwkAepQl45nzX0ulv bMjuJmWHTjvEeplnx9iual4J4BT/9FznFs7o4tFVVfYBacFrhWjQyAf2xoP3gyn3 5OlV55VHVB+oidXUVNSNHZbXwrd1sH42x7x8o17PDFJrWjiq4kAb2EfSOIuSS6na K9Y06bqh3yRbVtRdZOuCLcY8QJwt/mx//uQqG6NuSvYhx1QyC6g==XuDESOIuSSa -----END PGP PRIVATE KEY BLOCK----- 19 http://herraiz.org

  20. Keyservers Keyservers ● Internet hosts that contain public keys ● Federated services ● All servers contain all the public keys in the world ● Public keyserver in Spain thanks to RedIRIS ● URL: pgp.rediris.es 20 http://herraiz.org

  21. Message signing Message signing Hi there! Pub Pri Pub Pri Keyserver Pub Pub 21 http://herraiz.org

  22. Message signing Message signing Created with the private key Hi there! Pub Pri Pub Pri Keyserver Pub Pub 22 http://herraiz.org

  23. Message signing Message signing Hi there! Pub Pri Pub Pri Keyserver Pub Pub 23 http://herraiz.org

  24. Signing and encrypting Signing and encrypting Hi there! Pub Pri Pub Pri Keyserver Pub Pub 24 http://herraiz.org

  25. Signing and encrypting Signing and encrypting Pub FAD43A Pub Pri Pub Pri Keyserver Pub Pub 25 http://herraiz.org

  26. Signing and encrypting Signing and encrypting Pub FAD43A Pub Pri Pub Pri Keyserver Pub Pub 26 http://herraiz.org

  27. Signing and encrypting Signing and encrypting Hi there! Pub Pri Pub Pri Keyserver Pub Pub 27 http://herraiz.org

  28. Signing and encrypting Signing and encrypting Hi there! Pub Pri Pub Pri Keyserver Pub Pub 28 http://herraiz.org

  29. Identity certification Identity certification How do you know that public keys belong to their legitimate owners? Can we ensure that the Public key key does belong to Barack Obama Barack Obama? 29 http://herraiz.org

  30. Identity certification Identity certification Certificate Authorities Trust chain 30 http://herraiz.org

  31. Public key signing Public key signing ● Public keys are plain text documents that can be cryptographically signed ● Mutual public signing adds identity certification to PKP schemes 31 http://herraiz.org

  32. Public key signing Public key signing Barack Obama Pub Pri Pub Pri Keyserver Pub Pub 32 http://herraiz.org

  33. Public key signing Public key signing Barack Obama Key FE0A7AF2 Name Barack Obama Fingerprint D0DA E915 BFDD E5CD 8BA0 B159 7E97 2ACB FE0A 7AF2 Pub Pri Pub Pri Keyserver Pub Pub 33 http://herraiz.org

  34. Public key signing Public key signing Barack Obama Key FE0A7AF2 Name Barack Obama Fingerprint D0DA E915 BFDD E5CD 8BA0 B159 7E97 2ACB FE0A 7AF2 Pub Pri Pub Pri Keyserver Pub Pub 34 http://herraiz.org

Recommend

Public-Key Cryptography Public-Key Cryptography Lecture 9 Public-Key Cryptography Lecture 9

Public-Key Cryptography Public-Key Cryptography Lecture 9 Public-Key Cryptography Lecture 9

Public-Key Cryptography Public-Key Cryptography Lecture 9 Public-Key Cryptography Lecture 9 CCA Security SIM-CCA Security (PKE) Recv Send PK/Enc SK/Dec Replay Filter Secure (and correct) if: s.t. output of is distributed

1.26k views • 101 slides
Public-Key Cryptography Public-Key Cryptography Lecture 8 Public-Key Encryption Public-Key

Public-Key Cryptography Public-Key Cryptography Lecture 8 Public-Key Encryption Public-Key

Public-Key Cryptography Public-Key Cryptography Lecture 8 Public-Key Encryption Public-Key Cryptography Lecture 8 Public-Key Encryption Diffie-Hellman Key-Exchange PKE scheme PKE scheme SKE: Syntax KeyGen outputs K K Enc: M K R

1.18k views • 104 slides
Public Key Cryptography in Practice Eli Biham - May 3, 2005 c 372 Public Key Cryptography in

Public Key Cryptography in Practice Eli Biham - May 3, 2005 c 372 Public Key Cryptography in

Public Key Cryptography in Practice Eli Biham - May 3, 2005 c 372 Public Key Cryptography in Practice (13) How Cryptography is Used in Applications The main drawback of public key cryptography is the inherent slow speed of the public key

442 views • 14 slides
Lecture 7 Public Key Cryptography (Diffie-Hellman and RSA) 1 Public Key Cryptography

Lecture 7 Public Key Cryptography (Diffie-Hellman and RSA) 1 Public Key Cryptography

Lecture 7 Public Key Cryptography (Diffie-Hellman and RSA) 1 Public Key Cryptography Asymmetric cryptography Invented in 1974-1978 (Diffie-Hellman and Rivest-Shamir- Adleman) Two keys: private (SK), public (PK) Encryption:

810 views • 42 slides
Lecture 8 Public Key Cryptography (Diffie-Hellman and RSA) 1 Public Key Cryptography

Lecture 8 Public Key Cryptography (Diffie-Hellman and RSA) 1 Public Key Cryptography

Lecture 8 Public Key Cryptography (Diffie-Hellman and RSA) 1 Public Key Cryptography Asymmetric cryptography Invented in 1974-1978 (Diffie-Hellman and Rivest-Shamir- Adleman) Two keys: private (SK), public (PK) Encryption:

256 views • 22 slides
Lecture 8 Public Key Cryptography (Diffie-Hellman and RSA) 1 Public Key Cryptography

Lecture 8 Public Key Cryptography (Diffie-Hellman and RSA) 1 Public Key Cryptography

Lecture 8 Public Key Cryptography (Diffie-Hellman and RSA) 1 Public Key Cryptography Asymmetric cryptography Invented in 1974-1978 (Diffie-Hellman and Rivest-Shamir- Adleman) Two keys: private (SK), public (PK) Encryption: with

445 views • 17 slides
Public Key Cryptography Cryptography School of Engineering and Technology CQUniversity Australia

Public Key Cryptography Cryptography School of Engineering and Technology CQUniversity Australia

Cryptography Public Key Cryptography Concepts of Public Key Cryptography Public Key Cryptography Cryptography School of Engineering and Technology CQUniversity Australia Prepared by Steven Gordon on 20 Feb 2020, public.tex, r1803 1

421 views • 7 slides
Laconic Zero Knowledge to Public Key Cryptography Public Key Cryptography Akshay Degwekar

Laconic Zero Knowledge to Public Key Cryptography Public Key Cryptography Akshay Degwekar

Laconic Zero Knowledge to Public Key Cryptography Public Key Cryptography Akshay Degwekar (MIT) Public Key Encryption (PKE) [Diffie-Hellman76, Rivest-Shamir-Adelman78, Goldwasser-Micali82] pk sk Public Key Encryption Public Key Encryption

296 views • 25 slides
Outline CPSC 418/MATH 318 Introduction to Cryptography Public Key Cryptography, RSA Public-Key

Outline CPSC 418/MATH 318 Introduction to Cryptography Public Key Cryptography, RSA Public-Key

Outline CPSC 418/MATH 318 Introduction to Cryptography Public Key Cryptography, RSA Public-Key Cryptography 1 Renate Scheidler The RSA Cryptosystem 2 Department of Mathematics &amp; Statistics Department of Computer Science University of

372 views • 7 slides
Public Key Cryptography Diffie-Hellman Others CSS441: Security and Cryptography Sirindhorn

Public Key Cryptography Diffie-Hellman Others CSS441: Security and Cryptography Sirindhorn

CSS441 Public Key Crypto Principles RSA Public Key Cryptography Diffie-Hellman Others CSS441: Security and Cryptography Sirindhorn International Institute of Technology Thammasat University Prepared by Steven Gordon on 20 December 2015

461 views • 29 slides
Public-Key Cryptography Public-Key Cryptography Lecture 8 Public-Key Cryptography Lecture 8

Public-Key Cryptography Public-Key Cryptography Lecture 8 Public-Key Cryptography Lecture 8

Public-Key Cryptography Public-Key Cryptography Lecture 8 Public-Key Cryptography Lecture 8 Public-Key Encryption from Trapdoor OWP Public-Key Cryptography Lecture 8 Public-Key Encryption from Trapdoor OWP CCA Security El Gamal Encryption

1.78k views • 162 slides
Cryptography Public-Key Cryptography Uwe Egly Vienna University of Technology Institute of

Cryptography Public-Key Cryptography Uwe Egly Vienna University of Technology Institute of

Cryptography Public-Key Cryptography Uwe Egly Vienna University of Technology Institute of Information Systems Knowledge-Based Systems Group 1 / 18 Overview Problem of symmetric procedures: Exchange of secret key Solution: public-key

884 views • 18 slides
C) Public Key Cryptography C.a) Fundamentals C.b) RSA with Applications C.c) DSA and Diffie

C) Public Key Cryptography C.a) Fundamentals C.b) RSA with Applications C.c) DSA and Diffie

1 C) Public Key Cryptography C.a) Fundamentals C.b) RSA with Applications C.c) DSA and Diffie Hellman W. Schindler: Cryptography, B-IT, winter 2006 / 2007 2 C.a) Fundamentals 3 C.1 Introducing Remark Public key cryptosystems are widely

621 views • 47 slides
Handout 8 Summary of this handout: Asymmetric Cryptography Public Key Cryptography

Handout 8 Summary of this handout: Asymmetric Cryptography Public Key Cryptography

06-20008 Cryptography The University of Birmingham Autumn Semester 2012 School of Computer Science Eike Ritter 15 November, 2012 Handout 8 Summary of this handout: Asymmetric Cryptography Public Key Cryptography Diffie-Hellman Key

207 views • 8 slides
Lecture 7 Public Key Cryptography I: Encryption + Signatures [lecture slides are adapted from

Lecture 7 Public Key Cryptography I: Encryption + Signatures [lecture slides are adapted from

Lecture 7 Public Key Cryptography I: Encryption + Signatures [lecture slides are adapted from previous slides by Prof. Gene Tsudik] 1 Public Key Cryptography Asymmetric cryptography Invented in 1974-1978 (Diffie-Hellman and

478 views • 23 slides
Blended Cryptography: Public Key Infrastructure for Devices that dont Public key Phillip

Blended Cryptography: Public Key Infrastructure for Devices that dont Public key Phillip

Blended Cryptography: Public Key Infrastructure for Devices that dont Public key Phillip Hallam-Baker Principal Scientist VeriSign Inc. Small is not beautiful Not When you write the code PIC 16F88 368 bytes RAM 4K Word ROM 20MHz

390 views • 21 slides
Chapter3 Chapter3 Public-Key Cryptography and Public-Key Cryptography and Message

Chapter3 Chapter3 Public-Key Cryptography and Public-Key Cryptography and Message

Chapter3 Chapter3 Public-Key Cryptography and Public-Key Cryptography and Message Authentication Message Authentication Henric Johnson Blekinge Institute of Technology, Sweden http://www.its.bth.se/staff/hjo/ henric.johnson@bth.se Henric

576 views • 28 slides
Cryptography: Public Key Cryptography; Mathematical Preliminaries Greg Plaxton Theory in

Cryptography: Public Key Cryptography; Mathematical Preliminaries Greg Plaxton Theory in

Cryptography: Public Key Cryptography; Mathematical Preliminaries Greg Plaxton Theory in Programming Practice, Spring 2005 Department of Computer Science University of Texas at Austin Secure Communication Earlier we discussed the problems

202 views • 18 slides
Public-Key Cryptography Public-Key Cryptography Lecture 9 Public-Key Cryptography Lecture 9 El

Public-Key Cryptography Public-Key Cryptography Lecture 9 Public-Key Cryptography Lecture 9 El

Public-Key Cryptography Public-Key Cryptography Lecture 9 Public-Key Cryptography Lecture 9 El Gamal Encryption Public-Key Cryptography Lecture 9 El Gamal Encryption Public-Key Encryption from Trapdoor OWP Public-Key Cryptography Lecture

2.11k views • 163 slides
June 6, 2016 this week Public key cryptography Pieter van den Hombergh RSA and friends

June 6, 2016 this week Public key cryptography Pieter van den Hombergh RSA and friends

June 6, 2016 this week Public key cryptography Pieter van den Hombergh RSA and friends Crypto, PPK Public key cryptography Public and private Keys Information exchange Shared secret Authentication/signing Signing Pieter van den Hombergh

177 views • 7 slides
Tutorial on Public Key Cryptography RSA Eli Biham - May 3, 2005 c 386 Tutorial on Public

Tutorial on Public Key Cryptography RSA Eli Biham - May 3, 2005 c 386 Tutorial on Public

Tutorial on Public Key Cryptography RSA Eli Biham - May 3, 2005 c 386 Tutorial on Public Key Cryptography RSA (14) RSA the Key Generation Example 1. Randomly choose two prime numbers p and q . We choose p = 11 and q = 13. 2.

259 views • 22 slides
CSCI E-170 October 17, 2005 L04: Public Key Cryptography 1 Todays Outline 1. LJ Nonsense

CSCI E-170 October 17, 2005 L04: Public Key Cryptography 1 Todays Outline 1. LJ Nonsense

CSCI E-170 October 17, 2005 L04: Public Key Cryptography 1 Todays Outline 1. LJ Nonsense 2. HW2 - Graded and returned. 3. HW3 - How are things going? 4. Review of L03 (hash functions &amp; ciphers) 5. Public Key Cryptography 6.

757 views • 43 slides
Algorithms for Public Key Cryptography Eli Biham - May 3, 2005 c 408 Algorithms for Public

Algorithms for Public Key Cryptography Eli Biham - May 3, 2005 c 408 Algorithms for Public

Algorithms for Public Key Cryptography Eli Biham - May 3, 2005 c 408 Algorithms for Public Key Cryptography (15) Computing Square Roots Modulo a Prime We have already seen how to compute square roots modulo primes of the form p = 4 k + 3:

932 views • 34 slides
1 Symmetric algorithm Public key algorithm Secret key public key and private key C 1 = E

1 Symmetric algorithm Public key algorithm Secret key public key and private key C 1 = E

Cryptography security Cryptography may be a component of a secure system Cryptographic Systems Adding cryptography may not make a Authentication &amp; Communication system secure Protocols Paul Krzyzanowski Distributed Systems

753 views • 23 slides

More recommend