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Security Systems for Digital Data Big Brother is watching YOU Bernhard Hofer 03/10/2008 CIST 3100 - Organizations, Applica...
Table of contents <ul><li>History  and  Terminology </li></ul><ul><li>Cryptography nowadays  and Encrypting Digital Data <...
Beginning of cryptography <ul><li>Egypt‘s Old Kingdom   (4500+ years ago) non-standard hieroglyphs </li></ul><ul><li>The G...
Page  H  E  L  P  M E  I  A  M  … wood cylinder strip of paper
Terminology (I) <ul><li>c r y p t o g r a p h y </li></ul>kryptós, „hidden“ graphéin, „to write“ „ secret writing“
Terminology (II) Hello, this is my first english pres at UNO …  plaintext  (ordinary information) encryption  (converting ...
Table of contents <ul><li>History  and  Terminology </li></ul><ul><li>Cryptography nowadays  and Encrypting Digital Data <...
Cryptography nowadays (I) <ul><li>“ Cryptography is about communication in the presence of adversaries.” </li></ul><ul><li...
<ul><li>Symmetric key system  (private key) … sender and receiver share the same key   (for encryption and decryption) … l...
<ul><li>Asymmetric key system   (public key) … founded  1976  by Diffie and Hellman … 2 keys  (same lenght) : 1 public and...
Cryptography nowadays (IV) Key Server in a so called Trust Center Player 1 Player 2 public key private key …  delivering m...
Cryptography nowadays (VI) Key Server in a so called Trust Center Player 1 Player 2 public key private key …  delivering m...
<ul><li>Asymmetric key system   (public key) … full security, if process repeated twice …  operational area :   Combinatio...
Table of contents <ul><li>History  and  Terminology </li></ul><ul><li>Cryptography nowadays  and Encrypting Digital Data <...
<ul><li>The internet … local structure … none secure, open information system … private, public and economic player …  cry...
<ul><li>Requirements for secure interaction … availability … authentification … confidentiality … integrity … commitment <...
<ul><li>Useful applications …  PGP   (Pretty Good Privacy) RSA, IDEA    founded 1991 by Phil Zimmermann …  confidential ce...
<ul><li>The one and only security hole is Nothing and/ore nobody could save you against Brute Force Attacks ;-) </li></ul>...
cost increases per power (10.000 $, 100.000 $, 1.000.000 $, …) Key length in Bit Codebreaking timetable
Table of contents <ul><li>History  and  Terminology </li></ul><ul><li>Cryptography nowadays  and Encrypting Digital Data <...
<ul><li>In princible … … it is a old school symmetric encryption … nothing else as a key distributer … it isn‘t based on m...
<ul><li>In action … … first implemented between the BA CA and the Vienna City-Hall over a 1.500m FDDA (fibre optics) cabel...
Table of contents <ul><li>History  and  Terminology </li></ul><ul><li>Cryptography nowadays  and Encrypting Digital Data <...
<ul><li>…  for your attention!! </li></ul>Bernhard Hofer CIST 3100 - Organizations, Applications & Technology Thank you...
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Security Systems for Digital Data

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This was one presentation I held last year during my exchange semester at the University of Nebraska at Omaha.

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Security Systems for Digital Data

  1. 1. Security Systems for Digital Data Big Brother is watching YOU Bernhard Hofer 03/10/2008 CIST 3100 - Organizations, Applications & Technology
  2. 2. Table of contents <ul><li>History and Terminology </li></ul><ul><li>Cryptography nowadays and Encrypting Digital Data </li></ul><ul><li>Big Brother www </li></ul><ul><li>The Future (quantum cryptography) </li></ul><ul><li>Question time </li></ul>
  3. 3. Beginning of cryptography <ul><li>Egypt‘s Old Kingdom (4500+ years ago) non-standard hieroglyphs </li></ul><ul><li>The Greeks of Classical times The SCYTALE, used by Spartan military </li></ul>enlarge image
  4. 4. Page H E L P M E I A M … wood cylinder strip of paper
  5. 5. Terminology (I) <ul><li>c r y p t o g r a p h y </li></ul>kryptós, „hidden“ graphéin, „to write“ „ secret writing“
  6. 6. Terminology (II) Hello, this is my first english pres at UNO … plaintext (ordinary information) encryption (converting plaintext) decryption (reverse process) H?$% /&!!““= )(/&%ded die=? 30((&% ?$$?) … ciphertext (unreadable plaintext) cipher key +
  7. 7. Table of contents <ul><li>History and Terminology </li></ul><ul><li>Cryptography nowadays and Encrypting Digital Data </li></ul><ul><li>Big Brother www </li></ul><ul><li>The Future (quantum cryptography) </li></ul><ul><li>Question time </li></ul>
  8. 8. Cryptography nowadays (I) <ul><li>“ Cryptography is about communication in the presence of adversaries.” </li></ul><ul><li>Ronald Rivest , &quot;Cryptography&quot; From the Handbook of Theoretical Computer Science, edited by J. van Leeuwen, Elsevier Science Publishers B.V., 1990 </li></ul>
  9. 9. <ul><li>Symmetric key system (private key) … sender and receiver share the same key (for encryption and decryption) … like the wind (very fast) … 2 different kinds (block and stream ciphers) … Examples: D(A)ES, RC4, MD5, hash </li></ul>Cryptography nowadays (II)
  10. 10. <ul><li>Asymmetric key system (public key) … founded 1976 by Diffie and Hellman … 2 keys (same lenght) : 1 public and 1 private … both are different but related … slower than symmetric key methods </li></ul>Cryptography nowadays (III)
  11. 11. Cryptography nowadays (IV) Key Server in a so called Trust Center Player 1 Player 2 public key private key … delivering message !! Authentication Problem !! Player 2 doesn‘t know, who sent the message!?! Everybody knows the public key from Player 2! … wants to deliver a SECURE message encrypting … decrypting …
  12. 12. Cryptography nowadays (VI) Key Server in a so called Trust Center Player 1 Player 2 public key private key … delivering message !! Confidentiality Problem !! Player 2 knows, who sent the message! But: Everybody could decrypt the message from Player 1! continue pres. … wants to deliver a SECURE message encrypting … decrypting …
  13. 13. <ul><li>Asymmetric key system (public key) … full security, if process repeated twice … operational area : Combination of the symmetric and asymmectric … Examples: RSA, DSA, SSL, SSL2, … </li></ul>Cryptography nowadays (VIII)
  14. 14. Table of contents <ul><li>History and Terminology </li></ul><ul><li>Cryptography nowadays and Encrypting Digital Data </li></ul><ul><li>Big Brother www </li></ul><ul><li>The Future (quantum cryptography) </li></ul><ul><li>Question time </li></ul>
  15. 15. <ul><li>The internet … local structure … none secure, open information system … private, public and economic player … cryptography is the only way for privacy protection over the world wide web! </li></ul>Big Brother www (I)
  16. 16. <ul><li>Requirements for secure interaction … availability … authentification … confidentiality … integrity … commitment </li></ul>Big Brother www (II)
  17. 17. <ul><li>Useful applications … PGP (Pretty Good Privacy) RSA, IDEA founded 1991 by Phil Zimmermann … confidential certificates digital signature for online banking … SSL (Secure Socket Layer … https://) founded by Netscape, cryptography for web pages </li></ul>Big Brother www (III)
  18. 18. <ul><li>The one and only security hole is Nothing and/ore nobody could save you against Brute Force Attacks ;-) </li></ul>!! YOUR PASSWORD !! Big Brother www (IV)
  19. 19. cost increases per power (10.000 $, 100.000 $, 1.000.000 $, …) Key length in Bit Codebreaking timetable
  20. 20. Table of contents <ul><li>History and Terminology </li></ul><ul><li>Cryptography nowadays and Encrypting Digital Data </li></ul><ul><li>Big Brother www </li></ul><ul><li>The Future (quantum cryptography) </li></ul><ul><li>Question time </li></ul>
  21. 21. <ul><li>In princible … … it is a old school symmetric encryption … nothing else as a key distributer … it isn‘t based on mathematical … but on the physics of information </li></ul>Quantum cryptography (I)
  22. 22. <ul><li>In action … … first implemented between the BA CA and the Vienna City-Hall over a 1.500m FDDA (fibre optics) cabel in April 2004 </li></ul><ul><li>by Anton Zeilinger … </li></ul>Quantum cryptography (II)
  23. 23. Table of contents <ul><li>History and Terminology </li></ul><ul><li>Cryptography nowadays and Encrypting Digital Data </li></ul><ul><li>Big Brother www </li></ul><ul><li>The Future (quantum cryptography) </li></ul><ul><li>Question time </li></ul>
  24. 24. <ul><li>… for your attention!! </li></ul>Bernhard Hofer CIST 3100 - Organizations, Applications & Technology Thank you...

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