Abstract: A device, multilayer record carrier and method are given for providing information in a controlled way. The multilayer record carrier has spiral angle information to be applied and/or verified while accessing the content of the record carrier. Thereto a spiral angle (55) between two data layers of the multilayer record carrier is detected. The spiral angle indicates an actual rotational angle between a first predetermined location (51) on the first data layer (40) and a second predetermined location (52) on the second data layer (41). The spiral angle information and the spiral angle for controlling are combined for controlling said providing of information, e.g. for copy protection, various versions of software or for providing a parameter to identify the record carrier.

Abstract: A number of data items are selected for inclusion in a data set so as to discourage a transmission of the entire set over a limited bandwidth communications path, such as the Internet. Each data item comprises one or more sections, and the totality of sections constitute the complete data set. Each section of the data set contains a watermark that includes an identifier of the section, and an identifier of the data set. In a preferred embodiment, the identifier of the section is the address of the section, and the identifier of the data set is a serial number and an indicator of the total size of the data set. The presence of the data set is confirmed by checking the watermarks of randomly selected sections to verify that the original section that formed the data set is present. If a section is discovered to be missing or altered, subsequent processing of data items of the data set is prevented. In a preferred embodiment, the identifiers are stored as a combination of robust and fragile watermarks.

Abstract: A method of generating an authorization status list, comprising generating a run-length encoded representation of an authorization status of a number of devices and storing the representation in the authorization status list. Preferably comprises generating the representation by indicating, for each of a number of ranges of devices, the devices in a particular range having a same authorization status, the number of devices in each of said ranges, together with for each of said ranges the authorization status shared by the devices in each of said ranges. A range may then be omitted if it is of a predetermined length.

Abstract: This invention relates to an authentication method for authenticating a first party to a second party, where an operation is performed on condition that the authentication succeeds. If the first party is not authenticated, then if the first party qualifies for a subauthorization, the operation is still performed. Further, a device that comprises a first memory area holding a comparison measure, which is associated with time, and which is also used in said authentication procedure, a second memory area holding a limited list of other parties which have been involved in an authentication procedure with the device, and a third memory area, holding compliance certificates concerning parties of said list.

Abstract: In a method for providing copy-protection services on a storage medium (for instance a solid state memory module), the data are arranged in sectors to which a field (S4T) is associated, where said field contains a random value Ri which is changed randomly when writing data to said sector. By encrypting the data stored on the medium using a key which depends critically on said random numbers, bit-by-bit copies (apart from said random numbers, which can not be deterministically changed by an application) to a second storage medium or recopies from some intermediate storage medium, can not be decrypted because the values of said random numbers will have changed, thus preventing unauthorized duplication and replay attacks.

Abstract: The present invention relates to a content protection method and system as well as to a reproduction method and device providing copy protection of electronic content. In order to provide protection against illicit copying by consumers as well as by authoring and formatting facilities content-dependent encryption of the content is proposed. In an encryption step the content (C0) is encrypted using an application key (AK) and/or a disc key (DK). Further, a content-dependent content mark (AK?, H, MAC) is generated using said content (C0), which content mark is to be evaluated during decryption of said encrypted content (C2).

Abstract: The present invention relates to a record carrier (10) for storing user data in sectors (S) and management information (n) associated with said sectors. In order to provide a simple, low-cost, flexible and secure copy protection of the user data when being transmitted over a communication bus (6) of a PC it is proposed according to the present invention that the management information comprises an encryption indication information (M1) indicating that the user data stored in the associated sector (S) are to be encrypted by a read-out device (2) before being transmitted over a communication bus (6).

Abstract: To prevent copying of content on interfaces, a secure authenticated channel (SAC) must be set up. This requires authentication between devices. The invention proposes an authentication protocol where a first device (e.g. a PC) authenticates itself to a second device (e.g. a peripheral device) using a challenge/response protocol and a second device authenticates itself using a zero knowledge protocol, where preferably a secret of the zero knowledge protocol is scrambled and cryptographically bound to the key-block.

Abstract: The invention relates to a method, a device, a client-server system as well as a computer program product and computer program element for handling digital silence when fingerprinting digital media signals. A fingerprint comprising a number of sub-fingerprints for at least a part of the digital media signal is generated, (step 42), and the influence of at least one piece of the media signal on the fingerprint is removed or changed, (step 48), which piece corresponds to digital silence. The invention in a reliable way avoids a wrong identification of media signals, such as audio signals, where digital silence is included. The invention is also easy to implement by only requiring some of the functionalities already provided in a computer.

Abstract: The invention relates to a system for improved copy protection comprising a record carrier like a CD-RW+ or a DVD storing copy-protected information and a device for reading from and/or writing to the record carrier. For that the record carrier (1) has a first area (3) storing information (data), which is at least partly stored in encrypted form (EAK(data)), this part being called an asset (EAK(data)), and which includes a first part of decryption information (HCK, EDNK(HCK)), and the record carrier (1) further has a second area (4) storing a second part of decryption information (UCID), wherein both the first (HCK) and second (UCID) parts of decryption information serve in decrypting an asset (EAK(data)). Such distribution of decryption information over at least two areas of the record carrier may further be combined with additional safety mechanisms as e.g. hidden channels, encrypted keys, counter mechanisms, and revocation lists.

Abstract: The invention relates to methods and arrangements for processing a signal using a digital processor having a given word length.

Abstract: In whilelist-based authentication, a first device (102) in a system (100) authenticates itself to a second device (103) using a group certificate identifying a range of non-revoked device identifiers, said range encompassing the device identifier of the first device (102). Preferably the device identifiers correspond to leaf nodes in a hierarchically ordered tree, and the group certificate identifies a node (202-207) in the tree representing a subtree in which the leaf nodes correspond to said range. The group certificate can also identify a further node (308, 310, 312) in the subtree which represents a sub-subtree in which the leaf nodes correspond to revoked device identifiers. Alternatively, the device identifiers are selected from a sequentially ordered range, and the group certificate identifies a subrange of the sequentially ordered range, said subrange encompassing the whitelisted device identifiers.

Abstract: A digital media recorder and method of controlling such is shown. During attempts to copy media content such as audio or a video sequences, sub-sequences are extracted from an input media sequence. A digital fingerprint of the sub-sequence is calculated and compared with at least one first reference fingerprint from a database. The outcome of the comparison determines the action to take in the further processing. Recording of the input media sequence on the media carrier is either allowed or obstructed, e.g. disallowed. In the case recording of the sequence is allowed, the database is updated with information that the digital media sequence has been recorded. This has the effect of a “speed bump,” which limits the rate at which those copies of media content can be made, i.e. the effect is that of prohibiting more than a given number of copies within a given time frame.

Abstract: A certifying authority provides a method for whitelist-based controlling of authentication of a first device (102) in a system (100) to a second device (103). The method comprises issuing to the first device (102) a group certificate identifying a range of non-revoked device identifiers, said range encompassing the device identifier of the first device (102). Preferably the device identifiers correspond to leaf nodes in a hierarchically ordered tree, and the group certificate identifies a node (202-207) in the tree representing a subtree in which the leaf nodes correspond to said range. The group certificate can also identify a further node (308, 310, 312) in the subtree which represents a sub-subtree in which the leaf nodes correspond to revoked device identifiers. Alternatively, the device identifiers are selected from a sequentially ordered range, and the group certificate identifies a subrange of the sequentially ordered range, said subrange encompassing the whitelisted device identifiers.

Abstract: The invention relates to a method and an access control system for controlling access to content, said content being encrypted by content keys (F1, F2) stored in a key-locker (5) encrypted by a key-locker key (KLK).

Abstract: The present invention relates to a method of verifying the integrity of system data, particularly of copy protection information like an Effective Key Block or a Media Key Block including revocation data for revoking untrusted devices. At present cryptographic information relating to content-protection is prerecorded on disks. In order to avoid that this information is changed which poses a security risk, a cryptographic hash of the cryptographic information is stored on the disk in read-only manner according to a known method. However, the processing according to a known method is slow and increases the start-up time. This problem is solved according to the present invention by a method of verifying the integrity of system data, comprising the steps of: generating a cryptographic key from said system data, generating check data from said cryptographic key using a hash function, and verifying the integrity of said system data by comparing the generated check data with a trusted version of said check data.

Abstract: The invention relates to a method of storing a disc-ID on a record carrier (1) comprising tracks (4) in which information can be stored. This disc-ID comprises a predetermined fixed number of disc-ID bits (10). The disc-ID bits (10) are stored on the record carrier (1) in a scattered way. For example, the disc-ID bits (10) can be stored in groups of one disc-ID bit (1) and at positions reserved for storing non-data bits. The invention further relates to a device for reading the record carrier (1) with the scattered disc-ID, and to a record carrier (1).

Abstract: A method of secure transmission and reception of a message from a user. An image (320) representing a plurality of input means, e.g. an image of a keypad, is generated and encoded. The image is encoded using visual cryptography using a key sequence stored in a decryption device (310) as randomization. The randomized image is transmitted to the client device (301), where it is displayed on a first display (501) The randomization is displayed on a second display (311) Superimposing the first and second displays reveals the image. The client device (301) allows the user to select particular spots on the first display (501) that correspond to the location of particular input means on the reconstructed image. The coordinates of these spots are transmitted back to the server (300), which can translate them to the particular input means selected by the user. The message is then constructed as the input symbol represented by the particular input means.

Abstract: Apparatus and methods for attacking a screening algorithm. Content to be downloaded is identified. The identified content is then partitioned into at least two sections, wherein each of the at least two sections has a duration which is less than a duration of a threshold duration value assigned by the screening algorithm, and the partitioned content is subjected to a screening algorithm. Once the content has been successfully downloaded, the integrity of the downloaded content may be restored by reassembling the sections.