Precomputed and transactional mixing is believed to allow portable devices, such as smart phones, to send and receive messages, with little extra bandwidth or battery usage, while achieving anonymity for senders and recipients among all messages sent globally in batches defined by short time intervals. To learn anything about which inputs correspond with which outputs of such a batch of messages, the entire cascade of mix devices, each preferably operating independently in a different country, would it is believed have to be compromised. None of the real-time computation, neither by the mixes nor smartphones, uses full public-key operations—resulting it is believed in orders of magnitude performance improvement over previously-known systems. Aspects include untraceable return addresses, group chat, feed-following and large payloads. Transaction protocols include a variety of payments use cases. Limited anonymity and credential mechanism are based on a new approach to user identification disclosed, in which each user provides a small amount of different identifying information to each mix node, so that comparatively little is revealed to each node individually.

Techniques are described for transaction-based read and write operations in a distributed system. In an embodiment, an authorization protocol overlaid onto a transaction to control access to each of the data pools. Using the techniques described herein, the DTRS provides authorization mechanism to ensure that the entity, which hosts the data pool, may only access the data set from an originating entity based at least upon the access rules of the originating entity set for the data set. Additionally, the DTRS's read/write transactions keep the data pools of the DTRS in synch with each other, so each data pool stores the same data sets as another data pool of the DTRS. When a data integrity service of an entity generates a new data entry from a user transaction with a client application, a new write request is generated for the DTRS to which the data integrity service belongs. The DTRS receives the data entry and its metadata from the data integrity service and performs steps to update all data pool of the DTRS, in an embodiment.

Disclosed herein is a means that takes advantage of the immutable security provided by blockchain data structures and further implements measures that enable data in blockchain records to remain private to their respective users via the use of multiple ciphertexts that are subjected to zero-knowledge proofs and manipulated homomorphically. Ciphertexts make use of cryptographic key pair encryption where participants make use of public keys to encrypt data intended for one another alone.

Techniques for providing to a user with an anonymous user signature on a message in a distributed decentralized network are presented. The techniques use a hardware security module and a certificate authority. The certificate authority: obtains a credential that includes a certificate for the user, where the certificate includes a user public key and a plurality of user attributes; receives a request for a signature on the message, where the request includes an indication of a subset of the plurality of user attributes to be revealed; accesses from the hardware security module a user secret key; and provides to the user at least the message signed by the user secret key and a zero-knowledge proof that establishes that the message is signed by the user secret key corresponding to the user public key in the credential without revealing the plurality of user attributes.

An information processing apparatus generates, from a message including a public key of a user or an identifier associated with the public key and a random number, a commitment in which the message is concealed. The information processing apparatus generates signature information about a hash value of the random number by using a secret key associated with the public key. The information processing apparatus generates zero-knowledge proof information for proving that the user has knowledge of the random number, the message, and the public key. The information processing apparatus transmits the generated commitment, signature information, and zero-knowledge proof information to an information processing apparatus.

Disclosed herein are systems and techniques for using a content delivery network to perform various functions within a digital advertising ecosystem, in ways that yield technological benefits such as improved security, efficiency, and speed (for example, reduction in publisher load times). As one specific example, a content delivery network can be used for the creation of electronic tokens for user identity protection between demand side platforms, supply side platforms, content creators (for example, advertisers), and publishers.

Privacy preserving secure task automation. A method may include generating, by a first section of a platform, a pair of encryption keys (private and shared secret keys); receiving, by a second section of the platform, platform user data, trigger service user data; and action service user data, wherein the user of the services and platform are the same; sending the shared secret key to the services; storing the private key in the first section; receiving from the trigger service, by the second section, a first communication encrypted with the shared secret key, regarding occurrence of a trigger; determining, by the first section, that the trigger corresponds to the user of the platform; encrypting a second message with the shared secret key, requesting invocation of the action based on the trigger; and transmitting the second encrypted message to the action service without the data related to the user of the platform.

Embodiments described herein provide a privacy mechanism to protect user data when transmitting the data to a server that estimates a frequency of such data amongst a set of client devices. In one embodiment, a differential privacy mechanism is implemented using a count-mean-sketch technique that can reduce resource requirements required to enable privacy while providing provable guarantees regarding privacy and utility. For instance, the mechanism can provide the ability to tailor utility (e.g. accuracy of estimations) against the resource requirements (e.g. transmission bandwidth and computation complexity).

A computer-implemented method includes: determining assets held by a remitter, the assets to be spent in a remittance transaction between the remitter and one or more payees, in which each asset corresponds to a respective asset identifier, a respective asset amount, and a respective asset commitment value; determining a remitter pseudo public key and a remitter pseudo private key; determining a cover party pseudo public key, in which the cover party pseudo public key is obtained based on asset commitment values of assets held by the cover party; and generating a linkable ring signature for the remittance transaction.

The present invention relates generally to a system and method of querying an anonymized database. More particularly, the invention provides a method and system for querying an anonymized database without the need to decrypt queried data while it's processed. Even more specifically, the invention provides a method and system of anonymizing a database such that it may be queried efficiently in near real time while still retaining the ability to not decrypt requested data while it's being processed.