Abstract: A method is used in managing use of security keys. Based on a request for use of a key that serves as part of a data security system, a set of criteria to apply to the request is determined. The set of criteria pertain to security management of the key that is subject of the request. The set of criteria is applied to the request; and a result is determined based on the application of the set of criteria.

Abstract: A method is used in managing use of security keys. Based on a request for use of a key that serves as part of a data security system, a set of criteria to apply to the request is determined. The set of criteria pertain to security management of the key that is subject of the request. The set of criteria is applied to the request; and a result is determined based on the application of the set of criteria.

Abstract: Example embodiments of the present invention provide authenticated file system that provides integrity and freshness of both data and metadata more efficiently than existing systems. The architecture of example embodiments of the present invention is natural to cloud settings involving a cloud service provider and enterprise-class tenants, thereby addressing key practical considerations, including garbage collection, multiple storage tiers, multi-layer caching, and checkpointing. Example embodiments of the present invention support a combination of strong integrity protection and practicality for large (e.g., petabyte-scale), high-throughput file systems. Further, example embodiments of the present invention support proofs of retrievability (PoRs) that let the cloud prove to the tenant efficiently at any time and for arbitrary workloads that the full file system (i.e.

Abstract: A processing device comprises a processor coupled to a memory and implements a graph-based approach to protection of a system comprising information technology infrastructure from a persistent security threat. Attack-escalation states of the persistent security threat are assigned to respective nodes in a graph, and defensive costs for preventing transitions between pairs of the nodes are assigned to respective edges in the graph. A minimum cut of the graph is computed, and a defensive strategy is determined based on the minimum cut. The system comprising information technology infrastructure subject to the persistent security threat is configured in accordance with the defensive strategy in order to deter the persistent security threat.

Abstract: Example embodiments of the present invention provide authenticated file system that provides integrity and freshness of both data and metadata more efficiently than existing systems. The architecture of example embodiments of the present invention is natural to cloud settings involving a cloud service provider and enterprise-class tenants, thereby addressing key practical considerations, including garbage collection, multiple storage tiers, multi-layer caching, and checkpointing. Example embodiments of the present invention support a combination of strong integrity protection and practicality for large (e.g., petabyte-scale), high-throughput file systems. Further, example embodiments of the present invention support proofs of retrievability (PoRs) that let the cloud prove to the tenant efficiently at any time and for arbitrary workloads that the full file system (i.e.

Abstract: A secure solution is provided to the problem of secret key agreement. In particular, a method of reliable forward secret key sharing is disclosed between two legitimate correspondents whose profiles match sufficiently. The invention relies on a physical random function, sometimes referred to as a physical unclonable function (PUF) to provide a secure solution to the problem of secret key agreement. In one embodiment, a one-pass protocol is introduced based on Reed-Solomon codes leading to an unconditionally secure solution. In a further embodiment, the solution of the first embodiment is improved upon by providing a conditionally secure solution based on a pseudo random family of functions. In a still further embodiment, a two-pass protocol is introduced which is used exclusively for purposes of identification and authentication. In accordance with the principles of the two-pass protocol, two communications are required and unlike the one-pass protocol, the second correspondent selects the secret key K.

Abstract: A secure solution is provided to the problem of secret key agreement. In particular, a method of reliable forward secret key sharing is disclosed between two legitimate correspondents whose profiles match sufficiently. The invention relies on a physical random function, sometimes referred to as a physical unclonable function (PUF) to provide a secure solution to the problem of secret key agreement. In one embodiment, a one-pass protocol is introduced based on Reed-Solomon codes leading to an unconditionally secure solution. In a further embodiment, the solution of the first embodiment is improved upon by providing a conditionally secure solution based on a pseudo random family of functions. In a still further embodiment, a two-pass protocol is introduced which is used exclusively for purposes of identification and authentication. In accordance with the principles of the two-pass protocol, two communications are required and unlike the one-pass protocol, the second correspondent selects the secret key K.

Abstract: An information carrier includes runlength limited marks in a track. The runlengths of the marks represent main channel bits and variations of a further parameter of the marks representing secondary channel bits. Not all marks have the variations, only marks of at least a predetermined runlength have the variations.

Abstract: An information carrier includes runlength limited marks in a track. The runlengths of the marks represent main channel bits and variations of a further parameter of the marks representing secondary channel bits. Not all marks have the variations, only marks of at least a predetermined runlength have the variations.

Abstract: Recently developed methods for copy protection rely on a watermark detector to judge whether multimedia content can be copied or not. In such copy protection schemes, a watermark detector examines the multimedia content and outputs a signal (D) indicating whether a watermark is present or not. Known watermark detectors determine a decision variable (y) indicating to which extent the watermark is present, for example, the amount of correlation between the input signal and a reference copy of the watermark to be detected. The watermark is detected if the decision variable exceeds a predetermined threshold (y2). Such a detector is vulnerable to an attack which is described in this patent application.

Abstract: The invention relates to an information carrier comprising runlength limited marks in a track. The runlengths of the marks represent main channel bits and variations of a further parameter of the marks representing secondary channel bits. Not all marks have said variations, only marks of at least a predetermined runlength have said variations.

Abstract: A watermark detector is disclosed to judge whether multimedia content can be copied or not. The watermark detector examines the multimedia content and outputs a signal indicating whether a watermark is present or not. A decision variable indicating to which extent the watermark is present is determined, for example, the amount of correlation between the input signal and a reference copy of the watermark to be detected. The watermark is detected if the decision variable exceeds a predetermined threshold (y2). The detector also generates a random output signal for a predetermined range of decision values between the threshold (y2) and a further threshold (y1).

Abstract: Multiword information is encoded as based on multibit symbols in relative contiguity with respect to a medium, whilst providing wordwise interleaving and wordwise error protection code facilities. This may provide error locative clues across words of multiword groups, that originate in high protectivity clue words and point to low protectivity target words. The clue words may have a first uniform size and be interspersed in a first uniform manner. The target words may have a second uniform size and be interspersed in a second uniform manner. The organization may be applied for use with optical storage. Sectors may get provisional protectivity as a low-latency error correction mechanism.

Abstract: An encrypting exponentiation modulo M is effected by a modular multiplication X*YmodM, where M is a temporally steady but instance-wise non-uniform modulus. The method involves an iterative series of steps. Each step executes one or two first multiplications to produce a first result, and a trim-down reduction of the size of the first result by one or more second multiplications to produce a second result. The method furthermore takes a distinctive measure for keeping the final result of each step below a predetermined multiplicity of the modulus. In particular, the method postpones substantially any subtraction of the modulus as pertaining to the measure to a terminal phase of the modular exponentiation. This is possible through choosing in an appropriate manner one or more parameters figuring in the method. This further maintains overall temporal performance.

Abstract: Multiword information is based on multibit symbols disposed in relative contiguity with respect to a medium, and is encoded with a wordwise interleaving and wordwise error protection code for providing error locative clues across multiword groups. In particular, the clues originate in high protectivity clue words (BIS) that are interleaved among clue columns, and also in synchronizing columns constituted from synchronizing bit groups. The synchronizing columns are located where the clue columns are relatively scarcer disposed. The clues are directed to low protectivity target words (LDS) that are interleaved in a substantially uniform manner among target columns which form uniform-sized column groups between periodic arrangements of clue columns and synchronizing columns.

Abstract: A stream of channel bits, of a signal relating to a binary channel, is decoded into a stream of source bits, of a signal relating to a binary source. This binary channel includes a main channel and a secondary channel. This secondary channel is embedded in the main channel. Errors in the stream of secondary channel bits are corrected using a stream of corrected main channel bits. This stream of corrected main channel bits is reconstructed from a stream of corrected source bits. The secondary channel can be embedded in the main channel in different manners, e.g. via multi-level coding or via merging-bit coding.