Abstract: The claimed subject matter provides a method for revoking delegatable anonymous credentials. The method includes receiving a request to revoke an anonymous credential. The anonymous credential may be representative of an ability to prove non-membership in an accumulator for a first entity. The method also includes revoking the anonymous credential from the first entity in response to the request to revoke the anonymous credential. Additionally, the method includes revoking the anonymous credential from a second entity in response to the request to revoke the anonymous credential. The first entity delegates the anonymous credential to the second entity.

Abstract: A method implemented on a computing device provides for identifying the device and/or a user to an application on the device. The method comprises receiving a function call for a public identifier, responding to the function call, performing a hash operation and returning the public identifier. Responding to the function call comprises requesting a publisher ID from a first memory location within the device and requesting a private ID from a second memory location. Performing a hash operation on the publisher ID and the private ID creates the public identifier. The public identifier is then returned to the application. A method of allowing a developer to test an application on a mobile device or emulator is also described. A mobile device programmed to return a public identifier to an application is also described.

Abstract: The subject disclosure is directed towards a technology by which data is securely distributed using a homomorphic signature scheme and homomorphic network coding signature schemes. A homomorphic signature scheme for signing the data is based upon binary pairing with standard prime order groups. Sets of data are signed based upon dividing a larger block of data into smaller blocks, and separately signing each smaller block. The smaller blocks may be distributed to nodes of a network topology that are configured for network coding. In one alternative, the homomorphic signature scheme protects against changes to the block identifier. Proof data may be provided independent of a random oracle, may be provided by providing parameters for verification in a Groth-Sahai proof system, or may be provided by providing parameters for verification independent of a Groth-Sahai proof system.

Abstract: A Universal Serial Bus (USB) compatible storage device is utilized as a security token for storage of cryptographic keys. A cryptographic subsystem of a processor accesses cryptographic keys in containers on the USB compatible storage device. Accessing includes storing and/or retrieving. The processor does not include an infrastructure dedicated to the USB compatible storage device. Cryptographic key storage is redirected from an in-processor container to the USB compatible storage device. No password or PIN is required to access the cryptographic keys, yet enhanced security is provided. Utilizing a USB compatible storage device for a cryptographic key container provides a convenient, portable, mechanism for carrying the cryptographic key, and additional security is provided via physical possession of the device.

Abstract: Implementations for providing role-based distributed key management (DKM) replication are described. A server node receives a request from a requester node to perform a DKM create or update function. The server node determines the role of the requester node based on a public key of the requester node. The server node determines whether the role of the requester node indicates that the requester node is authorized to request the DKM create or update function. If the requester node's role is authorized to request the DKM create or update function, then the server node performs the requested function. The DKM create or update function may involve a replication function. Public key and trust chains may be derived from physical cryptographic processors, such as TPMs.

Abstract: The subject disclosure is directed towards processing requests for accessing a service provider. After examining at least one security token, a public key and a portion of attribute information are identified. An authentication component is accessed and applied to the public key. A unique user identifier is employed in generating the public key. The authentication component is generated using information from at least one revoked security token or at least one valid security token. The authentication component is configured to prove validity of the at least one security token.

Abstract: In an example, one or more cryptographic keys may be associated with a group. Any member of the group may use the key to encrypt and decrypt information, thereby allowing members of the group to share encrypted information. Domain controllers (DCs) maintain copies of the group's keys. The DCs may synchronize with each other, so that each DC may have a copy of the group's keys. Keys may have expiration dates, and any client connected to a DC may generate a new key when a key is nearing expiration. The various clients may create new keys at differing amounts of time before expiration on various DCs. DCs that store keys early thus may have time to propagate the newly-created keys through synchronization before other DCs are requested to store keys created by other clients. In this way, the creation of an excessive number of new keys may be avoided.

Abstract: Described herein are techniques for distributed key management (DKM) in cooperation with Trusted Platform Modules (TPMs). The use of TPMs strengthens the storage and processing security surrounding management of distributed keys. DKM-managed secret keys are not persistently stored in clear form. In effect, the TPMs of participating DKM nodes provide security for DKM keys, and a DKM key, once decrypted with a TPM, is available to be used from memory for ordinary cryptographic operations to encrypt and decrypt user data. TPM public keys can be used to determine the set of trusted nodes to which TPM-encrypted secret keys can be distributed.

Abstract: Techniques to allow a security policy language to accommodate anonymous credentials are described. A policy statement in a security policy language can reference an anonymous credential. When the policy statement is evaluated to decide whether to grant access to a resource mediated by the policy statement, the anonymous credential is used. The policy language can be implemented to allow one anonymous credential to delegate access-granting rights to another anonymous credential. Furthermore, an anonymous credential can be re-randomized to avoid linkage between uses of the anonymous credential, which can compromise anonymity.

Abstract: The claimed subject matter provides a method for revoking delegatable anonymous credentials. The method includes receiving a request to revoke an anonymous credential. The anonymous credential may be representative of an ability to prove non-membership in an accumulator for a first entity. The method also includes revoking the anonymous credential from the first entity in response to the request to revoke the anonymous credential. Additionally, the method includes revoking the anonymous credential from a second entity in response to the request to revoke the anonymous credential. The first entity delegates the anonymous credential to the second entity.

Abstract: Described herein are various technologies pertaining to constructions of a password-based authentication protocol that are configured to allow a user to register with and authenticate to an online service without the online service receiving a password or a deterministic function of the password of the user. When registering with an online service, a client computing device establishes a cryptographically strong random secret and stores an encryption of such secret with a data storage device. The storage device also never receives the password or a deterministic function of the password. When the user wishes to authenticate to the online service, the user employs her password to retrieve the encrypted secret from the storage device, decrypts such secret, and utilizes the decrypted secret to answer a cryptographically strong challenge provided to the user by the online service upon the online service receiving a username pertaining to such user.

Abstract: A weighted entropy pool service system and methods. Weights are associated with entropy sources and are used to estimate a quantity of entropy contained in data from the entropy sources. An interface is optionally provided to facilitate connecting user entropy sources to the entropy pool service. The quantity of entropy contained in the system is tracked as entropy is distributed to entropy consumers. A persistent entropy pool state file stores entropy across system restarts.

Abstract: Architecture that stores specific passwords on behalf of users, and encrypts the passwords using encryption keys managed by a distributed key management system. The encryption keys are stored in a directory service (e.g., hierarchical) in an area that is inaccessible by selected entities (e.g., administrative users) having superior permissions such as supervisory administrators, but accessible to the account components that need to access the unencrypted passwords. The distributed key management system makes the encryption key stored in the directory service available to all hardware/software components that need the key to encrypt or decrypt the passwords.

Abstract: In an example, one or more cryptographic keys may be associated with a group. Any member of the group may use the key to encrypt and decrypt information, thereby allowing members of the group to share encrypted information. Domain controllers (DCs) maintain copies of the group's keys. The DCs may synchronize with each other, so that each DC may have a copy of the group's keys. Keys may have expiration dates, and any client connected to a DC may generate a new key when a key is nearing expiration. The various clients may create new keys at differing amounts of time before expiration on various DCs. DCs that store keys early thus may have time to propagate the newly-created keys through synchronization before other DCs are requested to store keys created by other clients. In this way, the creation of an excessive number of new keys may be avoided.

Abstract: This description provides tools for providing integrated user experiences while allocating licenses within volume licensing systems. These tools may provide methods that include sending information for presenting licensing portals at recipient organizations. The licensing portals may include representations of properties licensed by the organizations, and may include indications of how many licenses remain available for allocation. The methods may include receiving and validating licensing requests. The tools may provide other methods that include requesting and receiving information for presenting the licensing portals, as well as requesting and receiving licensing-related actions from the licensing systems. The tools may provide still other methods that include receiving requests for information to present launch portals, with these requests incorporating user identifiers for particular end-users.

Abstract: A security system that uses a cryptographic key derived from human interaction with media. The system employs a set of parameters that includes user responses to graphical media and/or audio data, among other parameters. The architecture adds a fourth dimension to the conventional authentication means in order to make at least an offline attack on the key much more difficult. In addition to a standard set of parameters such as password, salt (random bits inserted into the encryption process) and iteration count, the system further utilizes information in the form of “what the user does” by presenting and prompting the user to interact with media in some way. The media can include audio information, video information, and/or image information, for example.

Abstract: A weighted entropy pool service system and methods. Weights are associated with entropy sources and are used to estimate a quantity of entropy contained in data from the entropy sources. An interface is optionally provided to facilitate connecting user entropy sources to the entropy pool service. The quantity of entropy contained in the system is tracked as entropy is distributed to entropy consumers. A persistent entropy pool state file stores entropy across system restarts.

Abstract: A Universal Serial Bus (USB) compatible storage device is utilized as a security token for storage of cryptographic keys. A cryptographic subsystem of a processor accesses cryptographic keys in containers on the USB compatible storage device. Accessing includes storing and/or retrieving. The processor does not include an infrastructure dedicated to the USB compatible storage device. Cryptographic key storage is redirected from an in-processor container to the USB compatible storage device. No password or PIN is required to access the cryptographic keys, yet enhanced security is provided. Utilizing a USB compatible storage device for a cryptographic key container provides a convenient, portable, mechanism for carrying the cryptographic key, and additional security is provided via physical possession of the device.