argument: PED A1 "Confidentiality and integrity of customers' PIN is assured" { supported by F1 "PED has a tamper proofing mechanism" F2 "There is a tamper proof sealed box around the PED" warranted by A2 "The tamper proofing mechanism guarantees that attempts to tamper the PED sealed box will cause data in transit to be deleted, lost or overridden (depending on the mechanism implemented)"{ warranted by DK1 "Defeating the tamper proofing mechanism requires more than 10 hours effort" DK2 "Defeating the tamper proofing mechanism cost more than $25,000" } A3 "The PED sealed box is really tamper proof" { supported by F3 "Communication outside the PED box is encrypted" warranted by DK3 "There is no need for an expensive EMV protocol implementation to enforce encrypted communication inside the PED box" } } A4 "There are attackers with high level of expertise " round 1 { supported by F4 "Motivation to obtain PIN is potential financial gain " round 1 warranted by DK4 "Incentive and expertise ( with some imagination ) represent enough ingredients to overcome tamper proofing mechanism "round 1 replacing DK2 with !DK2 } A5 "Failure in tamper proofing mechanism exposes security of PED sealed box"round 1 replacing A3 with !A3{ supported by F8 "Overcoming PED sealed box allows obtaining clear text PIN" round 1 warranted by DK6 "Clear text PIN can be obtained not only by tampering with the PED sealed box but also by other means such as by social engineering applied to the card holders"round 1 } A6 "Weak encryption does not protect PIN " round 1 replacing F3 with !F3{ supported by F6 "Only strong encryption protects PIN " round 1 warranted by A7 "PIN can be cracked if weak encryption is enforced" round 1 { supported by F7a "Weak encryption was applied" round 1 F7 "Time required to crack the encryption algorithm with brute force is reasonable to be achieved"round 1 warranted by A8 "There are people with physical access to the PED box for long periods "round 1 replacing DK1 with !DK1{ supported by F5 "Merchants and PED administrators are in a position to deal with the PED without raising suspicion "round 1 warranted by DK5 "Long term access to PED allows try-and-error or sophisticated methods to be used for overcoming PED tamper proofing mechanism "round 1 } } } A9 "Other mechanisms are applied to track activities of merchants and PED administrators" round 2 replacing A4 with DK2 & !A4{ supported by F10 "Recording from surveillance cameras helps to reconstruct some activities performed by merchants and administrators"round 2 F11 "Dual control policies helps to minimize risk of administrators misuse of the PED"round 2 } A10 "Encryption in communication inside and outside the PED box is assured" round 2 replacing F7 with DK3 & !F7a { supported by F9 "Communication protocol used inside and outside the PED has to enforce strong encryption" round 2 }