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QMCS 490 - Class Today. “Enigma” recap and finish The quiz/survey Next homework assignment Desktop Crypto implementations. Homework Assignment. Look up some things in Chapter 5 Use Moore’s Law to guess how large of a crypto key a DES Cracker-style computer can crack in a given year.
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QMCS 490 - Class Today • “Enigma” recap and finish • The quiz/survey • Next homework assignment • Desktop Crypto implementations R. Smith - University of St Thomas - Minnesota
Homework Assignment • Look up some things in Chapter 5 • Use Moore’s Law to guess how large of a crypto key a DES Cracker-style computer can crack in a given year. • Turn the calculation around and guess the year in which such a machine will be able to crack a key of a given size. • Print out Chapters 1 and 2. Look at pretty picture and diagrams. Read a few stories. Bring them to class on Monday. R. Smith - University of St Thomas - Minnesota
Desktop Crypto Implementations • File encryption • User controlled; sharing and separation on computer • Volume encryption • Device driver encrypts data written to the drive • Can’t boot without a password/phrase/key • Users can steal from each other • Everything is safe if stolen (and key is unknown) • Hard drive encryption • Fast crypto built into hard drive • Users can steal from each other • Crypto is harder to disable • Problem: how do we handle the key? R. Smith - University of St Thomas - Minnesota
Software Crypto Dilemmas • How do we keep the crypto safe? • What can ‘they’ subvert • Subversion examples • File encryption • Hard drive encryption • Access control protections R. Smith - University of St Thomas - Minnesota
Access Control for this class • For Access Control Examples • Three elements to consider • Operating system – always has full access • Owner (usually the creator) – always has full access • Everyone else – access may be restricted • To specify access on a file or other asset • Identify the owner • Identify permissions granted to everyone else, if any • Access permissions to grant • Read, write – usual meaning • Execute – if executable, may be executed by other users • Search – for directories: can’t read but can search R. Smith - University of St Thomas - Minnesota
Access Control for Crypto • Who owns the executable? • Who can modify it? • Who owns keys? R. Smith - University of St Thomas - Minnesota
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