An online system receives a content item including a link to a landing page and determines a likelihood the landing page violates an online system policy based on a structural similarity between the landing page and a web page violating the policy. To determine the likelihood, the online system determines a hierarchical structure associated with the web page violating the policy and an additional hierarchical structure associated with the landing page. The hierarchical structure represents a structure of at least a portion of the web page and the additional hierarchical structure represents a structure of a corresponding portion of the landing page. The online system compares the hierarchical structure and additional hierarchical structure. Based on the comparison, the online system computes a measure of dissimilarity between the hierarchical structure and additional hierarchical structure and determines a likelihood the landing page violates the policy based on the measure of dissimilarity.

In some embodiments, a method includes generating, based on distributed ledger data associated with a first distributed ledger-based network (DLN), distributed ledger data associated with a second DLN. The first DLN and the second DLN each is a fork and the distributed ledger data associated with the first DLN include account data associated with a set of accounts. The method includes generating a request to initiate a transaction between a first account and a second account. The method includes authenticating the transaction based on a protocol associated with the second DLN and without using a private cryptographic key of the first account. The method includes sending a signal indicating the transaction was authenticated and storing information associated with the transaction in the distributed ledger data associated with the second DLN.

In some examples, in response to a request from a client device for information relating to a transaction stored by a blockchain, a system identifies, using information stored in a distributed storage system that stores data for the blockchain, multiple data owner entities from which permissions are to be obtained for access of the information, and determines an authorization requirement for the information based on a smart contract. The system sends authorization information based on the authorization requirement to trigger a retrieval of authorization tokens from the identified data owner entities for access of the information, and sends the information to the client device in response to receiving the authorization tokens.

Methods, apparatus, systems and articles of manufacture (e.g., physical storage media) for software defined silicon security are disclosed. Example apparatus include a trusted agent determiner to (i) determine respective reputation scores associated with a plurality of agents in a mesh network, the plurality of agents associated with a plurality of semiconductor devices, respective ones of the semiconductor devices including circuitry configurable to provide one or more features, and (ii) select, based on the respective reputation scores, a first agent from the plurality of the agents to transmit a request to activate or deactivate at least one of the one or more features. Example apparatus also include an agent interface to, in response to the request, broadcast an activation or deactivation of the least one of the one or more features to the mesh network to cause the trusted agent determiner to update the reputation score of the first agent.

An authority transfer system comprising a client, a resource server, a server that receives, from the client, an authorization request requesting permission to access to a resource managed by the resource server, and a user terminal possessed by an owner of the resource is provided. The server registers a first user terminal in accordance with a registration request of the first user terminal being received from the first user terminal, and determines whether or not a registered second user terminal can be deregistered in accordance with a registration cancellation request being received from the first user terminal, and if it is determined that the second user terminal can be deregistered, authenticates the first user terminal or the second user terminal, and deregisters the second user terminal in accordance with the authentication.

Some embodiments of the invention provide a method for a trusted (or originator) device to modify the security state of a target device (e.g., unlocking the device) based on a securing ranging operation (e.g., determining a distance, proximity, etc.). The method of some embodiments exchanges messages as a part of a ranging operation in order to determine whether the trusted and target devices are within a specified range of each other before allowing the trusted device to modify the security state of the target device. In some embodiments, the messages are derived by both devices based on a shared secret and are used to verify the source of ranging signals used for the ranging operation. In some embodiments, the method is performed using multiple different frequency bands.

A diamond asset comprising one or more diamonds and an encryption chip is used to asset-back a cryptographic token that can be used to conduct transactions. The cryptographic token is written to a blockchain using a smart contract that is configured to enable a transaction associated with the token in response to two or more of: a signature by the encryption chip, a signature by the owner of the diamond asset, and a validation of a visual layout of the diamond asset.

A system and method for facilitating secure transfer of encrypted files and/or messages can facilitate the secure transfer of encrypted files to a receiving user. The system can include: a computer program for facilitating sending of an e-mail message to a receiving user, the e-mail message including at least a web address of a trusted provider and instructions about how to securely download encrypted files without the receiving user setting up an account or a password, the transfer of encrypted files being facilitated by a code sent to a telephone of the receiving user.

In one embodiment, a processor includes a memory hierarchy and a core coupled to the memory hierarchy. The memory hierarchy stores encrypted data, and the core includes circuitry to access the encrypted data stored in the memory hierarchy, decrypt the encrypted data to yield decrypted data, perform an entropy test on the decrypted data, and update a processor state based on a result of the entropy test. The entropy test may include determining a number of data entities in the decrypted data whose values are equal to one another, determining a number of adjacent data entities in the decrypted data whose values are equal to one another, determining a number of data entities in the decrypted data whose values are equal to at least one special value from a set of special values, or determining a sum of n highest data entity value frequencies.

Secure management of keys and identities of an object manufactured by a manufacturer having a manufacturer key pair, and a client having a client key pair, the management being carried out using a decentralized blockchain database. The method includes generation of a manufacturing key pair; and publication and recording, in the blockchain, of the decentralized object identifier used to obtain the public key of the object. When a client purchases the object from the manufacturer, the method includes providing, by the object manufacturer, the object identifier, and the public manufacturing key to the client; and updating the blockchain. When the object is switched on for the first time, the object enrolls itself by generation of a utilization key pair; auto-enrollment using the manufacturing key pair; and replacement, in the blockchain, of the public manufacturing key associated with the object identifier with the public utilization key associated with the object identifier.