Hardware Protection Against Software Piracy Tim Maude and Derwent Maude Communication of the ACM September 1984 Presentation by Gayathri Ramakrishnan

Summary of the Paper  Definition and classification of Software Piracy  Methods that were currently in use  Working of the Proposed System  Hardware Security Unit  Software Aspect  Automation of Software Encryption  Possible Methods of Attack

Hardware Security Unit  Hardware Security Unit Connected to Input- Output Port of the Computer  Each computer provided with public and private key  Private Key is hidden into the PROM of the Security unit and made electrically unreadable by fusing links connecting memory cells to the programming pins

Software Aspect A B C D - Program D A B C D A B C D A B Compiled Program Critical Steps Encrypted C Public Key Information Encrypted In the Program by vendor Final Program

Working of the System  At program start-up “decoding key” which contains information about the public key is passed to the security unit  Security unit deciphers the decoding key  Then program executes and pass encrypted instruction to the unit.  Security unit deciphers the instruction and value would be returned

Appreciative Comments Concepts explaining about introducing several levels of complexity 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 Comments Functioning of the Security unit has not been explained properly Functioning of the Security unit has not been explained properly Protection of the Private Key Protection of the Private Key Could be discovered ! Could be discovered ! Explanation about using public key cryptogram is very difficult to understand Explanation about using public key cryptogram is very difficult to understand

Questions Is this Software Protection Scheme reliable? Is this Software Protection Scheme reliable? Security unit lost, damaged or stolen ! Security unit lost, damaged or stolen ! How can we improve the system? How can we improve the system? PC Add on card?