Koninklijke Philips Corporation N.V.

Philips Electronics North America Corporation

Other

North American Philips Corporation

Nxp B.v.

Michael A Epstein

Martin C Rosner

Raymond J Krasinski

Antonius A M Staring

Michael S Pasieka

Rajiv Gupta

Robert M McDermott

Laszlo Hars

Douglas Allen Stanton

Mohamed S Abdel-Mottaleb

William Palmer Lord

Brian C Johnson

David W Cuccia

Frederic Grumiaux

Toine A M Staring

A security system assesses the response time to requests for information to determine whether the responding system is in physical proximity to the requesting system. Generally, physical proximity corresponds to temporal proximity. If the response time indicates a substantial or abnormal lag between request and response, the system assumes that the lag is caused by the request and response having to travel a substantial or abnormal physical distance, or caused by the request being processed to generate a response, rather than being answered by an existing response in the physical possession of a user. If a substantial or abnormal lag is detected, for example due to the fact that the information was downloaded from the Internet, the system is configured to limit subsequent access to protected material by the current user, and/or to notify security personnel of the abnormal response lag.

Temporal proximity to verify physical proximity

A system and method includes timing parameters within a node-verification protocol, such as OCPS, to facilitate a determination of the proximity of a target node to a source node. The node-verification protocol includes a query-response sequence, wherein the source node communicates a query to the target node, and the target node communicates a corresponding response to the source node. The source node establishes a lower bound on the distance between the source node and the target node based on a measure of the time required to effect this query-response sequence. The time required to effect this sequence includes the time required to communicate the query and response, as well as the time required to process the query and generate the response. The target node includes a measure of the time required to process the query and generate the response to the source node. The source node subtracts this time from the total query-response time to determine the time consumed for the communication. This communication time is compared to a threshold value to determine whether the target node is local or remote relative to the source node.

Verifying a node on a network

A security system assesses the response time to requests for information to determine whether the responding system is in physical proximity to the requesting system. Generally, physical proximity corresponds to temporal proximity. If the response time indicates a substantial or abnormal lag between request and response, the system assumes that the lag is caused by the request and response having to travel a substantial or abnormal physical distance, or caused by the request being processed to generate a response, rather than being answered by an existing response in the physical possession of a user. If a substantial or abnormal lag is detected, the system is configured to limit subsequent access to protected material by the current user, and/or to notify security personnel of the abnormal response lag.

A method of determining proximity between a root node and a leaf node in a network is presented. The method comprises computing a link proximity value between any two mutually connected nodes in the network. At an initial node, a proximity computation request message is sent containing a proximity counter to an intermediate node to which the initial node is connected. At an intermediate node, being connected to a first node and to a second node, upon receipt of the proximity computation request message containing a proximity counter from the first node, the computed link is added to a proximity value and passed on the proximity computation request message to the second node. At a final node, upon receipt of the proximity computation request message, the proximity between the root node and the leaf node is determined as the value indicated by the proximity counter.

Proximity detection method

A system and method determines the proximity of the target node to the source node from the time required to communicate messages within the node-verification protocol. The node-verification protocol includes a query-response sequence, wherein the source node communicates a query to the target node, and the target node communicates a corresponding response to the source node. The target node is configured to communicate two responses to the query: a first response that is transmitted immediately upon receipt of the query, and a second response based on the contents of the query. The communication time is determined based on the time duration between the transmission of the query and receipt of the first response at the source node and the second response is compared for correspondence to the query, to verify the authenticity of the target node.

Secure proximity verification of a node on a network

Authentication information () obtained by a device () at one level of a transformation sequence is securely communicated to another device () at another level of the transformation sequence. To assure that the communicated authentication information () is not merely a copy of previously communicated authentication information, each communication () includes an item () that the receiving device () can verify as having been recently generated.

Access authorization across processing devices

Data items are selected for inclusion in a data set so as to discourage a transmission of the entire set. Each data item includes section(s) which constitute(s) the complete data set. Each section contains a watermark that includes an identifier of the section, and an identifier of the data set. The identifier of the section may be the address of the section, and the identifier of the data set may be the 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. The identifiers may be stored as a combination of robust and fragile watermarks.

Protecting content from illicit reproduction by proof of existence of a complete data set via self-referencing sections

Content material is protected with a variety of watermarking processes. Different subsets of the protected content material are submitted to different watermarking processes. At the rendering device, a watermark detector is configured to detect one or more different watermarks. Only if the particular watermark(s) that the rendering device is configured to detect is removed from the protected content material will the rendering device permit the rendering of the protected material. If the particular watermark(s) that the rendering device is configured to detect is unpredictable, or if the particular segment that is protected by a particular watermark is undetectable, a wholesale removal of specific watermarks from the watermarked material will neither be efficient nor economically viable.

Using multiple watermarks to protect content material

An apparatus and method for random number generation, including a plurality of cross-connected latchesproviding at least two latch outputs (latchlatch) is provided. A first XORreceives the at least two latch outputs (latch, latch) as an input, and generates a mistake signal 'E' when its inputs do not match from the at least two latch outputs (latch, latch) being at different logic states. The mistake signal is compared with a previously stored mistake signal by a second XORto determine whether to obtain a random bit from a pseudo random stream of bits.

Method and apparatus for choosing a combination of logic for generating random numbers using a difference signal

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.

A memory element is provided in the recording medium that is readable but not writeable by external devices, and whose content changes each time select material is recorded onto the medium. The content of this memory element forms a unique encryption key for encrypting the content encryption key. This encrypted content encryption key is further encrypted using a public key that corresponds to a private key of the intended rendering device. Although the unique encryption key is determinable by reading and processing the content of the externally read-only memory element, the decryption of the content encryption key requires both the unique encryption key and the private key of the intended rendering device. Because the unique encryption key is based on a content value of the read-only memory element that is unique to each recording to the recording medium, a subsequent illicit re-recording of the original encrypted content material onto the recording medium (a replay attack) will not provide the same unique encryption key as the unique encryption key used to originally encrypt the content encryption key. Because the unique encryption key of the replay attack differs from the original unique encryption key used to encrypt the content encryption key, the rendering device will be unable to decrypt the content encryption key, and thereby will be unable to decrypt the content material, and the replay attack will fail.

Key distribution via a memory device

A watermark is encoded redundantly so as to provide effective copy protection. To assure a reliable detection of the watermark in the presence of a potentially faulty watermark detection process, some or all of the watermark is redundantly encoded. The number of redundant encodings of the watermark is selected so that upon modification of the watermarked material, sufficient redundancy exists so that the material can be identified as watermarked material, and the number of detected copies of the watermark is used to detect the modification. Statistical processes are employed to determine the presence or absence of the watermarks in the presence of a potentially faulty watermark detection process. Different criteria may be applied to the watermark detection process for the verification of the watermarked portions, based on the desired degree of confidence for determining whether the appropriate watermark is present or absent, and the desired degree of confidence for determining whether a modification has occurred.

Copy protection via redundant watermark encoding

In a limited-copy protection scheme, a check-out/check-in system is configured to a) verify that the receiving device is a certified conforming device, and b) verify that the device that checks-in content material is the same device that checked-out the content material. The verification of the receiving device is effected via a conventional certification process. The verification that the same device is used for check-in and check-out is effected via a secure challenge-response protocol. As contrast to a conventional contemporaneous challenge-response protocol, the system provides a challenge that is specific to the receiving device when the content material is checked-out, and verifies the appropriate response when the content material is checked-in. Because the challenge-response is specific to the receiving device, only the device that receives the challenge when the content material is checked-out can provide the appropriate response when the content material is checked-in.

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Spring Valley, NY, United States of America

Michael A Epstein