摘要:
In at least one implementation, described herein, P and Q1, . . . , Qn are public points on an elliptic curve over a finite field, but the ratios of Qi to P are private. Those ratios are the components (α1, . . . , αn) of a private key, where Qi=αi P. This implementation generates short digital ciphers (i.e., signatures), at least in part, by mapping a message M to a point T on the elliptic curve and then scaling that point T based upon the private key α to get S. At least one other implementation, described herein, verifies those ciphers by comparing pairing values of two pairs, where one pair is the public point P and the scaled point S and another pair is public Q and the point T. This implementation tests whether log(Q)/log(P)=log(S)/log(T), without computing any elliptic curve discrete logarithm directly.
摘要:
Various methods and apparatuses are provided for generating and verifying digital signatures. In certain methods and apparatuses digital signature generating logic encrypts data based on a Jacobian of a curve, said Jacobian having a genus greater than one. The logic is configured by parameter data so as to select at least one Gap Diffie-Hellman (GDH) group of elements relating to the curve. The logic also determines private key data and corresponding public key data and signs the identified data with the private key data to create a corresponding digital signature. In other methods and apparatuses, the signature generating logic encrypts data based on a Weil pairing on a Jacobian of at least one super-singular curve having a genus greater than one.
摘要:
Methods and apparatuses are provided for generating blind digital signatures using curve-based cryptography techniques. One exemplary method includes establishing parameter data for use with signature generating logic that encrypts data based on a Jacobian of at least one curve. Here, the parameter data causes the signature generating logic to select at least one Gap Diffie-Hellman (GDH) group of elements relating to the curve. The method also includes receiving first data that is to be blindly signed, determining private key data and corresponding public key data using the signature generating logic, and generating second data by signing the first data with the private key data using the signature generating logic. The second data includes the corresponding blind digital signature. In other implementations, the method may also include having additional logic, for example, in one or more other devices, determine if the blind digital signature is valid.
摘要:
A method and system for encrypting a first piece of information M to be sent by a sender [100] to a receiver [110] allows both sender and receiver to compute a secret message key using identity-based information and a bilinear map. The sender uses a bilinear map to encrypt a message M, producing ciphertext V to be sent from the sender [100] to the receiver [110]. The receiver [110] uses the bilinear map to decrypt V and recover the original message M. According to one embodiment, the bilinear map is based on a Weil pairing or a Tate pairing defined on a subgroup of an elliptic curve. Also described are several applications of the techniques, including key revocation, credential management, and return receipt notification.
摘要:
An embodiment of the present invention includes a system for communicating digital data from a preferably small battery powered device (e.g., key-chain or pocket-sized form-factor) to a personal electronic device (e.g., a smartphone such as an iPhone or a Nexus One). The communication mechanism of the present invention can be used as second factor authentication. The present invention can also be used as a key for accessing physical locations such as building. Alternatively, the present invention can be used as a manner for transmitting digital data to a personal electronic device such as a smart phone.
摘要:
In a geo-security system, a device receives RF signals from multiple distinct classes of RF communication systems and extracts location-dependent signal parameters. A current geotag is computed from the parameters by fuzzy extractors involving quantization of the parameters and Reed-Solomon decoding to provide a reproducible unique geotag. The current geotag is compared with a stored geotag, and a geo-secured function of the device is executed based on the result of the comparison. The use of multiple signal sources of different types, combined with special fuzzy extractors provides a robust geotag that allows both lower false rejection rate and lower false acceptance rate.
摘要:
An object of this ciphertext decryption rights delegation system is to enable conversion of PKE-system ciphertext into IBE-system encrypted ciphertext, and, in a delegation system with users using only an IBE system, of preventing restoration of the master-secret key generated by a PKG device (public key generation device) even when there is collusion attack between the ciphertext converter and a decryption rights delegatee. A ciphertext decryption rights delegation system realizes delegation of ciphertext decryption rights between a device used by a decryption rights delegator and a device used by a decryption rights delegatee. From the master-secret key stored in the PKG device which generates secret keys, a secret key of the IBE system and auxiliary information are generated, and a re-encryption key is generated based on this auxiliary information. When sharing content, ciphertext encrypted by the decryption rights delegator device is converted by a ciphertext conversion device using the re-encryption key, and the converted ciphertext is decoded by the decryption rights delegatee device using the IBE-system secret key.
摘要:
Methods, systems, and apparatus, including computer program products, for retaining the function of product activation schemes and other persistent state changes based on hardware identifiers, even when running in a virtual machine monitor. It can tie such schemes to a single identifier, e.g., a USB serial number, instead of the multiple hardware identifiers.
摘要:
A system for measuring power consumption by a mobile device corresponding to access of web pages is provided. The system includes: the mobile device, configured to access web pages via a wireless network; a power measurement device connected to a battery of the mobile device, configured to measure parameters related to power consumption; and a server, in communication with the mobile device and the power measurement device, configured to control the mobile device's access of web pages and control the power measurement device's measurement of parameters, to receive measurements from the power measurement device, and to process the received measurements so as to correlate the mobile device's access of a web page with an amount of power consumed corresponding to the mobile device's access of the web page.
摘要:
Systems and methods for supporting symmetric-bilinear-map and asymmetric-bilinear-map identity-based-encryption (IBE) key exchange and encryption schemes are provided. IBE key exchange schemes use an IBE encapsulation engine to produce a secret key and an encapsulated version of the secret key. An IBE unencapsulation engine is used to unencapsulate the encapsulated key. IBE encryption schemes use an IBE encryption engine to produce ciphertext from plaintext. An IBE decryption engine is used to decrypt the ciphertext to reveal the plaintext. The IBE unencapsulation engine and decryption engines use bilinear maps. The IBE encapsulation and encryption engines perform group multiplication operations without using bilinear maps, improving efficiency. IBE private keys for use in decryption and unencapsulation operations may be generated using a distributed key arrangement in which each IBE private key is assembled from private key shares.