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?