Abstract:
The aim of the present invention is to enforce the watermarking on a content received by a client device, in particular to compressed video content. The present invention proposes a method to watermark a compressed content encrypted by at least one content key (CA key), said content key as well as pre-marking data forming CAS data, said CAS Data being encrypted by a transmission key and comprising at least one signature to authenticate all or part of the CAS Data, said compressed content being received by a client device comprising : - a Descrambler (103) having an input to receive the encrypted compressed content and an output to produce an compressed content, - a WM inserter (104) directly connected to the output of the Descrambler, said Descrambler and said WM inserter being connected with the Conditioner (200), said Conditioner executing the following steps : - receiving the CAS Data, - decrypting the CAS Data with the transmission key, - verifying the signature of the CAS Data, and if the signature is valid, - transferring the content key (CA key) to the descrambler (103) and the pre-marking data to the WM inserter, - watermarking by the WM inserter, the decrypted content received by the descrambler using the pre-marking data and the identifier.
Abstract:
Various arrangements for encrypting multiple television channels are presented. A first television channel of a plurality of television channels to be protected via a first entitlement control message (ECM) using a first encryption scheme may be designated. The plurality of television channels may be transmitted using a single transponder stream. A second television channel of the plurality of television channels to be protected via a second ECM encrypted using a second encryption scheme while the first television channel of the plurality of television channels is protected using the first encryption scheme may be designated. The first and second ECMs may be transmitted to a plurality of television receivers. Data from the first ECM may be used for descrambling of the first television channel by the plurality of television receivers. Data from the second ECM may be used for descrambling of the second television channel by the plurality of television receivers.
Abstract:
A method for securely obtaining a control word in a chip set of a receiver, said control word for descrambling scrambled content received by the receiver, the method comprising, at the chip set: receiving a secured version of a virtual control word from a conditional access/digital rights management client communicably connected to the chip set; obtaining the virtual control word from the secured version of the virtual control word; and using a first cryptographic function to produce a given output from an input that comprises the virtual control word and either a plurality of signature verification keys or one or more values derived from a plurality of signature verification keys, each signature verification key being associated with a conditional access/digital rights management system, the given output comprising at least one control word, wherein the first cryptographic function has the property that it is infeasible to determine a key pair including a signature key and a signature verification key and an input for the first cryptographic function comprising the determined signature verification key or one or more values derived, at least in part, from the determined signature verification key, such that the first cryptographic function produces the given output from the determined input.
Abstract:
Provided is a transmitting/receiving method and device for providing a conditional access broadcasting service. A transmitting method for providing a conditional access broadcasting service includes generating a control word (SI 10) for scrambling by- encoding a conditional access subscriber's, and changing the encoded data into an entitlement control message and an entitlement management message including the data generated by classifying the conditional access subscriber and a non-subscriber by activating the data (S120). Also, the method includes generating a final stream by multiplexing (S130) the entitlement control message, the entitlement management message, and a base stream for a first broadcasting service (SI 40), generating a base layer frame and an enhancement layer frame (SI 50) based on the final stream and an enhancement layer stream for a second broadcasting service, generating a broadcasting signal by hierarchically modulating (SI 60) the base layer frame and the enhancement layer frame, and transmitting the broadcasting signal.
Abstract:
The present invention concerns the field of broadcast encryption method, i.e. a method to organize the distribution of keys into a group of users so that it is possible to manage the revocation of one member of the group in an efficient way. The proposed solution is a private encryption key ciphertext constant collusion- resistant broadcast encryption. The main idea behind the invention is to mix the notion of efficient tree-based key derivation (also called subset management) with individual and personalized key blinding thus achieving a full collusion-resistant broadcast encryption system. The key de-blinding is performed at the last moment thanks to a cryptographic technique called pairings (also known as bilinear maps) resulting in a global key commonly shared by all authorized (non-revoked) devices. It should be noted that only non-revoked devices can compute the final key (this is achieved through subset management and related subset key derivation technique) and perform the de-blinding (which is performed with one pairing).
Abstract:
A sink may be to used to process multimedia digital data. The sink may include a plurality of input ports, an output port, a switchably-enabled selector to select an input port from a plurality of HDMI input ports to couple to an output port, a control circuit to detect encrypted data in a channel of the input ports; and a plurality of decryption engines. Each of the decryption engines may be coupled to respective input ports to synchronize with a corresponding encryption engine of a data source after the control circuit detects encrypted data in the channel of the respective input port. Additional circuitry may be included to operate the sink in a power saving mode. Also, methods for processing the data in both power saving and non-power saving modes.
Abstract:
A method and system for embedding a watermark in block encrypted content, including encoding a bit string, the bit string including n bits, denoted b 0 - b n-1 , the encoding including translating each bit, b 0 - b n-1 , into a block of data, according to the following rule if b i = 1, then translate b i into a block of data of a first type, and if b i = 0, then translate b i into a block of data of a second type, thereby translating the n bits into n blocks of data corresponding to each bit b 0 - b n-1 , arranging a composite block of data including the n blocks of data, and at least one additional block indicating the presence of the n blocks of data, and inserting the composite block of data into a content item as a watermark, wherein the watermarked content item is encrypted using an ECB mode of encryption. Related methods and apparatus are also described.
Abstract:
A method for monitoring an execution of a sequence of instructions of a data processing program (PR) in a security module (SM) associated to a multimedia unit (MU) connected to a managing center (MC) supplying control messages (ECM, EMM) authorizing the multimedia unit (MU) to access broadcast audio video content data streams. The security module (SM) comprises at least one processor (CPU) executing the data processing program instructions, a memory (M), and a monitoring module (MM) for analyzing the instructions before execution by the processor (CPU). The managing center (MC) comprises a security module emulator (EM) generating reference data sets (REF) by executing a sequence of instructions induced by data of a given control message (ECM, EMM) in the data processing program (PR). The reference data sets (REF) are appended to control messages (ECM, EMM) sent to the security module (SM) for verification. The monitoring module (MM) analyses a sequence of instructions of the data processing program (PR) for determining a check data set (CD) which is compared with a reference data set (REF) received from the control messages (ECM, EMM). When the reference data set (REF) matches with the check data set (CD), the data processing program (PR) continues its execution. Otherwise, the monitoring module (MM) sends an instruction (INT) to the processor (CPU) preventing further processing of the control messages (ECM, EMM) by the security module (SM).