8 Cracking Cracking Magnitude of piracy All kinds of digital content music software movies Huge economic repercussions Cracking Process of attacking a ID: 469417
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Slide1
Dr. Miguel Ángel Oros Hernández
8. CrackingSlide2
Cracking
Magnitude
of
piracyAll kinds of digital content (music, software, movies)Huge economic repercussionsCrackingProcess of attacking a copy protection technologyOne kind of reversingModification of an application’s binary to cause or prevent a specific key branch in the program’s executionSlide3
Cracking
Piratería y protección de copias
Tipos de protección
Conceptos avanzados de protecciónMarca de aguaSlide4
Piratería y protección de copiasSlide5
Piratería y protección de copiasSlide6
Piratería y protección de copias
Applying
reverse
engineering until the software cracker reaches the subroutine that containts the primary method of protecting the softwareElimination of the expiration period from a time-limited trial of an applicationScanning for the use of a commercial copy protection application (CD, DVD)CloneCDAlcohol 120%
Game Jackal
Daemon ToolsSlide7
Piratería y protección de copias
The
open
architecture of today’s personal computers makes impossible to create an uncrackable copy protection technologySlide8
Piratería y protección
de
copias
Class breakProblem in practically every copy protection technologyTakes place when a security technology or product fails in a way that affects every user of that technology or product, and not just the specific system that is under attackHuge efforts
of developers of
copy protection technologiesProblemPublishing the results of defeating the protection mechanismSlide9
Piratería y protección de copias
copy
protection mechanismDefinitionA delicate componentInvisible to legitimate usersDesign considerationsResistance to AttackEnd-User TransparencyFlexibilitySlide10
Tipos de protecciónSlide11
Tipos de protección
Media-
Based
ProtectionsThe primary copy protection approach in the 1980sIdea: have a program check the media with which it is shipped and confirm that it is an originalFloppy disks: creating
special “bad
” sectorsPrograms:CopyWriteTranscopyAre they legals?Serial numbersIdea: the software vendor ships each copy of the software with a unique serial number printed somewhere on the product package or on the media itselfThe installation requires this numberIf the program is installed, the user is registeredWhen the user contact customer support, the software vendor can verify that the user has a valid installation of the productSlide12
Tipos de protección
Challenge
response and online
activationsThe program sends a challenge response (an protocol used for authenticating specific users or computers in networks)Idea: the both parties share a secret key that is known only to themImprovement to the
serial numberChallenge
responseVendor’s approvalCrackable: create a keygen program that emulates the server´s challegne mechanism and generate a valid response on demandSlide13
Tipos de protección
keygen
A license or product
key generator (sometimes stylized as keygen) is a computer program that generates a product licensing key, serial number, or some other registration information necessary to activate for use a software applicationSlide14
Tipos de protección
Hardware-
based
protectionsIdea: add a tamper-proof, non-software-based component into the mix assists in authenticating the running softwareUse of attached chip to the computer like USBSlide15
Conceptos avanzados de protecciónSlide16
Conceptos avanzados de protección
Cripto-Processors
A
well-known software copy protection approachProposedRobert M. BestIdea: design a microprocessor that can directly executed encrypted code by decrypting it on the flyHard to crack because the decrypted code would never be accessible
to attackers
Digital Rights ManagementDRM ModelsEncrypting the protect contentTry their best to hide the decryption key and control the path in which content flows after it has been decryptedSlide17
Conceptos avanzados de protección
Digital
Rights
ManagementThe Windows Media Rights ManagerIdea: separate the media from the licence file (encryption key required to decrypt and playback the media file)Digital Rights ManagementSecure Audio PathAttempts to control the flow of copyrighted, unencrypted audio within WindowsProblem:
anyone can write a
simulated audio device driver that would just steal the decrypted content while the media playback software is sending it to the sound cardSlide18
Marca de aguaSlide19
Marca de agua
Watermaking
Processing
to adding an additional “channel” of imperceptible data alongside a visible stream of dataInvisble (or inaudible) data stream that is hidden within the filePropertiesDifficult to removeIt contains as much information as possibleImperceptibleDifficult to detect
EncryptedRobustSlide20
Marca de agua
aplicaciones
Enabling
authors to embed indentifying information in their intellectual propertyIdentifying the specific owner of an individual copy by using a watermarked fingerprintIdentifying the original,unmodified data through a validation markSlide21
Bibliografía
Reversing: Secrets of Reverse Engineering
Eldad Eilam
Wiley Publishing, Inc.2005Slide22
Fin