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Encoding and encryption

Encoding and encryption

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Encoding and encryption

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  1. Encoding and encryption Overview of encodings and ciphers in real life Juraj Vančo 93. prístav vodných skautov a skautiek Tortuga Trenčín Sep 2013

  2. Agenda • Encoding and encryption • Encodings in real life • Morse code • Where to find • Q codes • QSL • SSL encryption • Digital signature

  3. Encoding and encryption • Encoding • procedure with goal to change information to be easier in practise • every information needed to proceed is available for everyone • example: Morse code • Encryption • procedure with goal to hide information that cannot be read from those who do not have the knowledge how to extract (decrypt) the useful information • example: private translation table

  4. Encodings in real life • Pictograms, abbreviations with the only meaning • Morse code • Where? Telegraph + air communication: aviation, navy, HAM radio • Information: table + procedure • Lossless compression / decompression (LZHA = zip, gzip, bzip, rar) (information accumulation) • Information: procedure = algorithm • Email encodings with base64 algorithm • Information: procedure = algorithm

  5. Morse code • What for? Frequency band and filtering • Timing encrypted • Consequences: messaging (transmitting) procedure can take much time compared to speech => issues with oscillators characteristics bias in time • Solution: timing as fast as human can (200 letters / min) • Solution: using Q-codes (encodings) • Dots and lines? No use case in real life… • Replacement: phone (codes and spelling alphabet)

  6. Q codes • 3 letters codes replacing more complex information • Examples: • QSL • QTH • QSO • QRA • QRL

  7. Example of QSO »QRL? »CQ CQCQ de OM4ATN «OM4ATN de HB9ASD K »HB9ASD de OM4ATN TNX FER QSO QTH QTH TRENCIN RST 577 NAME JURAJ PSE QSL K «OM4ATN de HB9ASD TNX UR RST 599 QTH QTH GENEVA NAME JEAN WX CLOUDY PSE UR WX UR WX K »HB9ASD DE OM4ATN TNX FER QSL WX WX SUNNY 23C K «OM4ATN DE HB9ASD R R OK DR JURAJ TNX CU K »HB9ASD DE OM4ATN TNX CU SK

  8. Encryption in real life • Private translation table (can have additional key= shift etc.) • Code Navaho (table= key) • Security = Privacy, Integrity, Authentication • Symmetric and asymmetric encryption algorithms (AES, DES, 3DES, DSA, RSA…)- (known algorithm, unknown key) • Challenge: decrypt! • Scouting: messages that are “easy” to decrypt but take time (“4 ohne, Boj o pokladkapitána pirátov”) • IT- compute power: bunch of methods => easy to find the translation • Algorithm based encryption= no key= vulnerable algorithm • Key based= algorithm is known= find the key (brutal force attack)

  9. Encryption: symmetric and asymmetric • Keys: both must know the key, how to?

  10. Authentication: certificates & PKI

  11. Example of certificate #1

  12. Example of certificate #2

  13. Example of certificate #3

  14. Digital signature • Hash = Digitally encoded „abstract“ • integrity number, no real information inside • Digital signature = hash + certificate

  15. Other risks • Unsecured WiFi network • Running untrusted software without certification (Windows) • Use sigverif.exe in Windows command prompt • Unknown hardware • Keyboards, computers, fingerprint scanners…

  16. Q & A • Thanks for watching