EP1076857A1 - Protection contre la copie assuree sur un support memoire au moyen de la randomisation des emplacements et des cles lors d'un acces "ecriture" - Google Patents

Protection contre la copie assuree sur un support memoire au moyen de la randomisation des emplacements et des cles lors d'un acces "ecriture"

Info

Publication number
EP1076857A1
EP1076857A1 EP00918799A EP00918799A EP1076857A1 EP 1076857 A1 EP1076857 A1 EP 1076857A1 EP 00918799 A EP00918799 A EP 00918799A EP 00918799 A EP00918799 A EP 00918799A EP 1076857 A1 EP1076857 A1 EP 1076857A1
Authority
EP
European Patent Office
Prior art keywords
data
block
storage medium
copy
key
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP00918799A
Other languages
German (de)
English (en)
Inventor
Antonius A. M. Staring
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Koninklijke Philips NV
Original Assignee
Koninklijke Philips Electronics NV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Koninklijke Philips Electronics NV filed Critical Koninklijke Philips Electronics NV
Priority to EP00918799A priority Critical patent/EP1076857A1/fr
Publication of EP1076857A1 publication Critical patent/EP1076857A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F12/00Accessing, addressing or allocating within memory systems or architectures
    • G06F12/14Protection against unauthorised use of memory or access to memory
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/00086Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
    • G11B20/0021Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving encryption or decryption of contents recorded on or reproduced from a record carrier
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F12/00Accessing, addressing or allocating within memory systems or architectures
    • G06F12/14Protection against unauthorised use of memory or access to memory
    • G06F12/1408Protection against unauthorised use of memory or access to memory by using cryptography
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/00086Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/00086Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
    • G11B20/00094Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving measures which result in a restriction to authorised record carriers
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/00086Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
    • G11B20/00094Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving measures which result in a restriction to authorised record carriers
    • G11B20/00115Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving measures which result in a restriction to authorised record carriers wherein the record carrier stores a unique medium identifier
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/00086Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
    • G11B20/00094Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving measures which result in a restriction to authorised record carriers
    • G11B20/00123Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving measures which result in a restriction to authorised record carriers the record carrier being identified by recognising some of its unique characteristics, e.g. a unique defect pattern serving as a physical signature of the record carrier
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/00086Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
    • G11B20/0021Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving encryption or decryption of contents recorded on or reproduced from a record carrier
    • G11B20/00485Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving encryption or decryption of contents recorded on or reproduced from a record carrier characterised by a specific kind of data which is encrypted and recorded on and/or reproduced from the record carrier
    • G11B20/00492Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving encryption or decryption of contents recorded on or reproduced from a record carrier characterised by a specific kind of data which is encrypted and recorded on and/or reproduced from the record carrier wherein content or user data is encrypted
    • G11B20/00507Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving encryption or decryption of contents recorded on or reproduced from a record carrier characterised by a specific kind of data which is encrypted and recorded on and/or reproduced from the record carrier wherein content or user data is encrypted wherein consecutive physical data units of the record carrier are encrypted with separate encryption keys, e.g. the key changes on a cluster or sector basis
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/00086Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
    • G11B20/0021Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving encryption or decryption of contents recorded on or reproduced from a record carrier
    • G11B20/00485Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving encryption or decryption of contents recorded on or reproduced from a record carrier characterised by a specific kind of data which is encrypted and recorded on and/or reproduced from the record carrier
    • G11B20/00557Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving encryption or decryption of contents recorded on or reproduced from a record carrier characterised by a specific kind of data which is encrypted and recorded on and/or reproduced from the record carrier wherein further management data is encrypted, e.g. sector headers, TOC or the lead-in or lead-out areas
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10Digital recording or reproducing
    • G11B20/12Formatting, e.g. arrangement of data block or words on the record carriers
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10Digital recording or reproducing
    • G11B20/10527Audio or video recording; Data buffering arrangements
    • G11B2020/10537Audio or video recording
    • G11B2020/10546Audio or video recording specifically adapted for audio data
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B2220/00Record carriers by type
    • G11B2220/60Solid state media

Definitions

  • the invention relates to a method for providing copy-protection to a data storage medium, in particular to solid state memory modules.
  • a data storage medium in particular to solid state memory modules.
  • Arguments in favor are based on weight, power and shockproofness considerations.
  • ID unique identification code
  • Known anti-copying solutions use a unique identification code (ID) that is 'engraved' in the storage medium. At some point in time, this may be disadvantageous because of privacy considerations. Furthermore, as will be explained below, methods which 5 mainly rely on such an ID do not provide adequate protection against a copying scheme known as a 'replay attack'.
  • the present invention is particularly suited for solid state memory modules which provide easy random access to any location in the memory, be it on the basis of a bit, a byte or on some other entity such as a uniform sized sector that relates to the access width of the memory in question.
  • the invention is characterized in that the data on the storage medium are encrypted with a key K which depends on the position (Li, L 2 , L 3 ) of the data on the storage medium, and that in each write operation the data is stored in locations on the storage medium that are chosen at random.
  • the invention also relates to a system arranged for implementing a method as claimed in claim 1, a player for playing a recording prepared according to a method as claimed in claim 1, and a record carrier prepared according to a method as claimed in claim 1. Further advantageous aspects of the invention are recited in dependent Claims.
  • Figure 1 shows a conceptual two-player arrangement
  • Figure 2 illustrates the mechanism of 'replay attacks' in the prior art.
  • Figure 3 shows a schematic diagram of a storage medium embodiment;
  • Figure 4 shows an example of a file structure
  • Figures 5A and 5B illustrate an example of a method in accordance with the invention and how this method prevents 'replay attacks'.
  • Figures 6A and 6B illustrate a further example for a method in accordance with the invention.
  • FIG 1 illustrates a conceptual two-player arrangement, with two players A and B, and a removable module C that may be transposed between the players. As shown, both players have appropriate means for inserting the module. In the rest of the discussion it is assumed that this removable module may be accessed by other means as well (e.g. PC based readers). This poses the risk of unauthorized copying of the data on the module, assuming that the players A and B do not allow unauthorized copying.
  • the preferred embodiments are described in relation to a Solid State Audio player and module, although the invention may be used in a broader context. Within a few years, Solid State Audio (SSA) players are expected to become a new standard for portable audio playback devices.
  • SSA Solid State Audio
  • One of the tools for copy protection of digital content is encryption. While encryption by itself does not prevent illegal copying, it does render such copies useless, as the original content can be retrieved only by decrypting it using the proper key. As a result, playback of the content is limited to those devices that have access to that key. It is an objective of the copy protection system to manage the keys in such a way that illegal copying is prevented, while at the same time not inconveniencing legal and intended use of the content.
  • Most of the memory modules for solid state multimedia storage applications comprise a large flash memory and an on-board controller. The controller may or may not be integrated, and multiple separate memory chips may be employed on the module.
  • multimedia memory modules are: Memory Stick (Sony), SmartMedia (SSFDC Forum), Miniature Card (MC Forum), Compact Flash (PCMCIA Forum), Multimedia Card (MMC Association).
  • these devices can be thought of as block devices, similar to hard disk drives, where memory accesses occur by addressing sectors (typically 512 bytes) on the module.
  • sectors typically 512 bytes
  • some of the modules listed above employ the ATA interface standard, which is used to connect hard disks and other peripherals to a PC. This enables easy duplication (bit by bit) of the content of such memory modules using a PC.
  • Other modules use a proprietary interface and command set, but still are block based, i.e. individual sectors on the module can be addressed and modified.
  • a SSA player employs detachable memory modules, which can be accessed by other means as well (e.g. PC based readers).
  • One known solution is to embed a unique identification code (ID) in the memory module, which can be read by the application, but which can not be changed. This identification code can then be used to generate an encryption key, which is specific for the module.
  • ID unique identification code
  • Another known solution is to make use of defects in the memory modules, which naturally occur as a result of the manufacturing processes used to fabricate cheap but high storage capacity flash memories.
  • the locations of these natural defects probably will be unique for each module, and as such can act as a 'fingerprint' of that device. Again, a unique key can be generated, which is specific for the module.
  • a 'replay attack' is a form of copying in which an unauthorized copy is made from one system (system 1) to another (system 2), where the unauthorized (but unplayable copy) on system 2 can be used to restore a playable copy on system over and over again, even after expiration of the original copy.
  • Figure 2 illustrates this in more detail.
  • Each system comprises a unique identification code, represented by EDI for system 1 and ED2 for system 2, and contains files in which the content is stored as a sequence of separate blocks.
  • the data in respect of rights and usage on the original copy are encrypted with a key that is derived from IDl and a secret S.
  • Figure 3 represents a schematic diagram of a memory module embodiment 20.
  • the storage area 30 has an access time that is substantially independent of the physical storage location.
  • the controller 22 controls the access to the storage proper.
  • Various subsystems have been shown therein, the host interface 24, the memory interface 26, and the file system 28. External write and internal selection to the memory are shown as well.
  • the Application Programming Interface API the following functionality should be present.
  • an optional volume number is outputted that is either uniquely fixed and hard-wired, or a random number that is generated each time the command is executed. This number may only be changed when executing the formatting command, thereby destroying all data on the device.
  • the copy protection proper does not expressly need this number.
  • a reusable file ID is produced for later referencing the file in question.
  • a sector number is produced that is a random choice from the free block list.
  • the sector number that is produced can be the actual sector number in which the data proper were stored during the write operation, or it can be the sector number will be stored during the next write operation. This amongst others is possible in solid state audio devices without appreciable loss of time because the flash memory is not hampered by a seek time as is common in disk based systems. Such random choice in addition helps to level wear over the entire device.
  • the application may use or discard the sector number returned by the block write command as required.
  • the file ID controls outputting the data proper and the sector number of the current or next block to be read.
  • Figure 4 illustrates an example of a file structure, that is distributed into blocks, each having the size of a single sector of 512 bytes.
  • the first block carries information regarding the file, while the others have the file data proper.
  • the above organization will block the making of a bit wise copy of the module, inasmuch as no modification facility for individual sectors has been provided. Copying to an intermediate storage location and subsequently recopying the data on the module (which constitutes the 'replay attack' as explained above) will copy the data to completely different locations. This in itself provides some protection against copying. Copy protection is further provided by encrypting a data block through a key that is derived from a secret and also from the location (for instance and preferably the sector number) where the data in question is stored.
  • the latter information may be derived from the block write function that returns the sector number of the next file sector. As this information is not available for the first block, the latter may be used for less sensitive data. This limitation is overcome by letting the file create function return the sector number of the first sector in the file where the data proper (e.g. the file info) will be written. For reading, the present or next sector number is available before reading of the actual data, allowing the application to calculate the proper decryption key in time.
  • the encryption key thus combines the location of the storage, and a method that renders it impossible to predict this location. Copying will change the storage location, and in consequence will break the relation between location and decryption key.
  • the secret used in the derivation of the key may be a globally shared secret between all players, or may be derived by other methods well known to those skilled in the art.
  • Figures 5A and 5B illustrate a method in accordance with the invention. Each time data blocks are written, the controller 22 writes the data in randomly chosen locations. In Figures 5 A and 5B the locations are indicated by Li, L 2 etc. The data are encrypted with a key which is dependent on a secret S and a location L; or a combination of locations L, (for instance the location of the block that is written, or of the previous block, or of the block that is written and the previous block etc). Making a copy of the data of the memory module will (see Figure 5B) change in a irreproducible manner the locations of the data. In fact such will happen twice.
  • FIGS. 6A and 6B show an embodiment of the invention in which all data are encrypted with a key K (which may consist of a single key or a block of keys), that itself is stored encrypted with a key K' , which is the output of a hash function having as arguments the locations Li, L 2 , L 3 etc and a secret S. K' thus depends on the positions of the data blocks, in this case on the total sequence in which the data blocks are written.
  • K which may consist of a single key or a block of keys
  • controller may be provided in the system apart from the memory module, preferably the controller unit by which the random locations are chosen is integrated in the memory module. This makes it difficult to circumvent the method or influence the choice of locations of data.
  • the locations where the data, preferably arranged in blocks, are stored are chosen by a (preferably built-in) controller on a random basis.
  • a controller preferably built-in controller on a random basis.

Abstract

Dans un procédé assurant des services de protection contre la copie sur un support mémoire, les emplacements où sont stockées les données, qui sont de préférence arrangées sous forme de blocs, sont sélectionnés par un dispositif de commande (lui-même intégré) sur une base aléatoire. Le fait d'utiliser une clé de chiffrement qui dépend nécessairement de la position des données sur le support mémoire rend virtuellement impossible le déchiffrement des données copiées.
EP00918799A 1999-03-15 2000-03-14 Protection contre la copie assuree sur un support memoire au moyen de la randomisation des emplacements et des cles lors d'un acces "ecriture" Withdrawn EP1076857A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP00918799A EP1076857A1 (fr) 1999-03-15 2000-03-14 Protection contre la copie assuree sur un support memoire au moyen de la randomisation des emplacements et des cles lors d'un acces "ecriture"

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
EP99200776 1999-03-15
EP99200776 1999-03-15
EP00918799A EP1076857A1 (fr) 1999-03-15 2000-03-14 Protection contre la copie assuree sur un support memoire au moyen de la randomisation des emplacements et des cles lors d'un acces "ecriture"
PCT/EP2000/002276 WO2000055736A1 (fr) 1999-03-15 2000-03-14 Protection contre la copie assuree sur un support memoire au moyen de la randomisation des emplacements et des cles lors d'un acces 'ecriture'

Publications (1)

Publication Number Publication Date
EP1076857A1 true EP1076857A1 (fr) 2001-02-21

Family

ID=8239984

Family Applications (1)

Application Number Title Priority Date Filing Date
EP00918799A Withdrawn EP1076857A1 (fr) 1999-03-15 2000-03-14 Protection contre la copie assuree sur un support memoire au moyen de la randomisation des emplacements et des cles lors d'un acces "ecriture"

Country Status (5)

Country Link
EP (1) EP1076857A1 (fr)
JP (1) JP2002539557A (fr)
KR (1) KR20010043582A (fr)
CA (1) CA2332008A1 (fr)
WO (1) WO2000055736A1 (fr)

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JP2002132585A (ja) 2000-10-20 2002-05-10 Sony Corp 情報記録装置、情報再生装置、情報記録媒体、および情報記録方法、情報再生方法、並びにプログラム提供媒体
US6925342B2 (en) * 2000-12-05 2005-08-02 Koninklijke Philips Electronics N.V. System and method for protecting digital media
JP4944355B2 (ja) * 2001-05-22 2012-05-30 ユーキューイー,エルエルシー デジタル作品を記録する記録担体、方法及び装置
EP1466250A2 (fr) * 2001-10-12 2004-10-13 Koninklijke Philips Electronics N.V. Appareil et procede de lecture ou d'ecriture de donnees utilisateur
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Also Published As

Publication number Publication date
KR20010043582A (ko) 2001-05-25
CA2332008A1 (fr) 2000-09-21
WO2000055736A1 (fr) 2000-09-21
JP2002539557A (ja) 2002-11-19

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