A method for providing authentication of a user of a recipient unit when the recipient unit is off-line includes storing one or a plurality of one-time challenge-reply sets based on an on-line communication with a sender unit. In one example, each of the one-time challenge-reply sets includes at least a one-time challenge-reply pair for use in off-line authentication of the user for a particular resource available through the recipient unit. When the user is offline, the method includes selecting at least one of the plurality of stored one-time challenge-reply sets for off-line authentication of the user for the particular resource available through the recipient unit. The one-time challenge-reply sets may be associated with an article.

A computer generates a third encrypted polynomial that corresponds to a result of encrypting a third polynomial by use of a result of multiplying a first encrypted polynomial by a second encrypted polynomial, and outputs cryptographic information that represents the third encrypted polynomial. The first encrypted polynomial is a polynomial obtained by encrypting a first polynomial that corresponds to a first vector, and the second encrypted polynomial is a polynomial obtained by encrypting a second polynomial that corresponds to a second vector. The third polynomial includes a first term that has a coefficient based on an inner product of the first vector and the second vector and a second term other than the first term, in which a coefficient of the second term is masked.

An encryption apparatus includes a setting generator configured to generate an increasing function parameter regarding a predetermined one-way increasing function and a secret key necessary for encryption, and an encryptor configured to generate a first order-preserving encryption area regarding a plaintext using the one-way increasing function where the increasing function parameter is applied, generate a second encryption area regarding the plain text using the secret key, and generate a ciphertext by concatenating the generated first encryption area and the generated second encryption area.

Computer-implemented methods and systems are provided that receive, at an implantable medical device (IMD), a programming package comprising a collection of configuration change requests, transaction credentials, and a signature indicative of a source of the programming package. The transaction credentials include a first hash of the collection of configuration change requests. The IMD validates an external device as the source by decrypting the signature using a key that is uniquely associated with the external device. The IMD verifies the transaction credentials and the configuration change requests of the programming package, and generates a second hash of the collection of configuration change requests. Responsive to both (i) the second hash matching the first hash and (ii) the transaction credentials and the configuration change requests being verified, the IMD executes the collection of configuration change requests to update an operating configuration of the IMD.

Media content is delivered to a variety of mobile devices in a protected manner based on client-server architecture with a symmetric (private-key) encryption scheme. A media preparation server (MPS) encrypts media content and publishes and stores it on a content delivery server (CDS), such as a server in a content distribution network (CDN). Client devices can freely obtain the media content from the CDS and can also freely distribute the media content further. They cannot, however, play the content without first obtaining a decryption key and license. Access to decryption keys is via a centralized rights manager, providing a desired level of DRM control.

A system and methods for permitting open access to data objects and for securing data within the data objects is disclosed. According to one embodiment of the present invention, a method for securing a data object is disclosed. According to one embodiment of the present invention, a method for securing a data object is disclosed. The method includes the steps of (1) providing a data object comprising digital data and file format information; (2) embedding independent data into a data object; and (3) scrambling the data object to degrade the data object to a predetermined signal quality level. The steps of embedding and scrambling may be performed until a predetermined condition is met. The method may also include the steps of descrambling the data object to upgrade the data object to a predetermined signal quality level, and decoding the embedded independent data.

Technologies for establishing and managing a connection with a power line communication network include establishing a communication connection between an electronic device and a security server. A default device encryption key associated with the electronic device is changed to correspond with a new device encryption key of the security server. Thereafter, the electronic device may only join a power line communication network of a particular security server using a network membership key, which is encrypted with the device encryption key that the particular security server associates to the electronic device. The electronic device contains a circuit interrupt to interrupt a circuit of the electronic device if the electronic device is not able to successfully decrypt the network membership key.

Methods and systems are provided for securing an integrated circuit device against various security attacks, such as side-channel attacks. By limiting the number of different challenge vectors that can be combined with a critical variable of an encryption operation, it becomes more difficult to create enough side channel measurements to successfully perform statistical side-channel analysis.

In one exemplary embodiment of the invention, a method and computer program include: receiving first and second ciphertexts having first and second data encrypted per an encryption scheme, the encryption scheme has public/secret keys and encryption, decryption, operation and refresh functions, the encryption function encrypts data, the decryption decrypts ciphertext, the operation receives ciphertexts and performs operation(s) on them, the refresh operates to prevent growth of the magnitude of noise for a ciphertext while reducing the modulus of the ciphertext without using the secret key, utilizing a modulus switching technique that involves transforming a first ciphertext c modulo q into a second ciphertext c modulo p while preserving correctness, the technique includes scaling by p/q and rounding, p<q; using the operation function(s), performing operation(s) on them to obtain a third ciphertext; and reducing a noise level of the third ciphertext using the refresh function.

A signal is transmitted at a high speed in a direction opposite to a transmitting direction of a main large-capacity channel. A first transmitting unit transmits a first signal including a clock component to an external device through a transmission path as a differential signal. A second transmitting unit superimposes a second signal including a clock component on the transmission path as an in-phase signal to transmit to the external device. A state notifying unit communicates with the external device through a pair of differential transmission paths included in the transmission path and notifies the external device of a connection state of its own device by a DC bias potential of at least one of the pair of differential transmission paths.