hardware protection against software piracy tim maude and derwent maude communication of the acm...
TRANSCRIPT
Hardware Hardware Protection Against Protection Against
Software PiracySoftware PiracyTim Maude and Derwent Tim Maude and Derwent
MaudeMaudeCommunication of the ACMCommunication of the ACM
September 1984September 1984
Presentation byGayathri Ramakrishnan
Summary of the PaperSummary of the Paper Definition and classification of Software Definition and classification of Software
PiracyPiracy Methods that were currently in useMethods that were currently in use Working of the Proposed SystemWorking of the Proposed System
Hardware Security UnitHardware Security Unit Software AspectSoftware Aspect
Automation of Software EncryptionAutomation of Software Encryption Possible Methods of AttackPossible Methods of Attack
Hardware Security UnitHardware Security Unit
Hardware Security Unit Connected to Hardware Security Unit Connected to Input-Output Port of the ComputerInput-Output Port of the Computer
Each computer provided with public Each computer provided with public and private keyand private key
Private Key is hidden into the PROM of Private Key is hidden into the PROM of the Security unit and made electrically the Security unit and made electrically unreadable by fusing links connecting unreadable by fusing links connecting memory cells to the programming pinsmemory cells to the programming pins
Software AspectSoftware AspectA
B
C
D-
Program
D
A
B
C
D
A
B
C
D
A
B
CompiledProgram
Critical Steps
EncryptedC
PublicKey
InformationEncrypted
In theProgram by
vendor
FinalProgram
Working of the SystemWorking of the System
At program start-up “decoding key” At program start-up “decoding key” which contains information about the which contains information about the public key is passed to the security unitpublic key is passed to the security unit
Security unit deciphers the decoding key Security unit deciphers the decoding key Then program executes and pass Then program executes and pass
encrypted instruction to the unit.encrypted instruction to the unit. Security unit deciphers the instruction Security unit deciphers the instruction
and value would be returnedand value would be returned
Appreciative CommentsAppreciative Comments
Concepts explaining about Concepts explaining about introducing several levels of introducing several levels of complexity in the systemcomplexity in the system
Begin Point:= unit(3,8,0); Case point of 1:GOTO 1; 3: GOTO 2; 6: GOTO 3; END;1: sieve := sieve –[ j ]; Case point of 1 :GOTO 4 ; 2: GOTO 9; 3: GOTO 7 END;
2: primes := primes + [ next ]; Point := unit( 1,next,0 );
Unit(3,8,0)
Value :1
Unit(8,1)
Value :2
Security Unit
Critical CommentsCritical Comments
Functioning of the Security unit has not Functioning of the Security unit has not been explained properlybeen explained properly
Protection of the Private Key Protection of the Private Key
Could be discovered !Could be discovered !
Explanation about using public key Explanation about using public key cryptogram is very difficult to cryptogram is very difficult to understandunderstand
QuestionsQuestions
Is this Software Protection Scheme Is this Software Protection Scheme reliable?reliable?
Security unit lost, damaged or Security unit lost, damaged or stolen !stolen !
How can we improve the system?How can we improve the system?
PC Add on card?PC Add on card?