michael mckay mmckayiscubedcom bryan feir mailtobryansglcrestechca wrote course one player key broken dealing rest became known plaintext attack rest player keys went like row dominos actual followup xing player break interesting mere knowledge known plaintext corresponding input output necessarily make trivial break properly designed systems andor algorithm primary reason easy css css key 40bits thereby easy break exhaustive search attacks 40bits speculated misunderstanding government cryptography export rules time even interesting least soon xing player break people started studying css algorithm rapidly found serious design flaws left 40bit css algorithm actual strength around 23bits memory new attacks might reduced strength another great example showing proprietary cryptography algorithms viewed greatest suspicion tue sep 03 2002 090340pm 0400 yannick gingras wrote make wonder relative protection smart cards internal procession unit around 4mhz consider trusted hardware yes put limited amount trust smart card number clever attacks smartcards ross anderson uk documented quite smartcard manufactures usually one step behind attacks well designed system assumes system smartcard completely compromised point giving adversary secrets contained smartcard cryptography industry developed variety techniques reduce impact compromise including unique keys per smartcard forward security techniques luciano rocha strangenskyiorg wrote problem piece hardware trustworthy rest pc isnt cracker needs simulate locksmart card peek executable lock deactivated going back original question encrypted material goes outside trusted hardware impossible unbreakably protect may mitigation steps take sdmi watermarking schemes date easily broken another consideration value trying protect thing unbreakable adding cost terms price hasslefactor greatly improve protection since talking use standard pc workstations presume trying protect valuable im afraid security measures dont come free michael mckay director software development mmckayiscubedcom information security systems services inc 19925 stevens creek blvd cupertino ca 95014 phone 4087257136 x 4138 fax 4089737239 wwwiscubedcom thu 19 sep 2002 144422 0700 secure sofware key