Patent application number | Description | Published |
20120159189 | MODULAR EXPONENTIATION RESISTANT AGAINST SKIPPING ATTACKS - An exponentiation method resistant against skipping attacks. A main idea of the present invention is to evaluate, in parallel with the exponentiation such as y=g | 06-21-2012 |
20120290634 | MODULAR EXPONENTIATION METHOD AND DEVICE RESISTANT AGAINST SIDE-CHANNEL ATTACKS - A modular exponentiation comprising iterative modular multiplications steps and taking as input a first modulus N, a secret exponent d and a base x. During at least one modular multiplication step aiming at computing a result c from two values a, b and the first modulus N so that c=a·b mod N, a processor takes as input the two values a, b and the first modulus N from which are obtained two operands a′, b′ and a second modulus N′ using operations with at most linear complexity—at least one of the two operands a′, b′ is different from the two values a, b, and the two operands a′, b′ are different when a is equal to b—so that the modular multiplication c=a·b mod N from a side-channel viewpoint behaves like a modular squaring except for when a′ equals b′. | 11-15-2012 |
20120321075 | FAULT-RESISTANT EXPONENTIATIONI ALGORITHM - A method for performing a m-ary right-to-left exponentiation using a base x, a secret exponent d and a modulus N, wherein m is a power of 2. A device having a processor and m+1 registers R[ | 12-20-2012 |
20130195267 | PUBLIC KEY ENCRYPTION SYSTEM BASED ON THE QUADRATIC RESIDUOSITY ASSUMPTION - A public-key encryption system. Encryption of a k-bit plaintext m is performed by picking a random generating ciphertext and outputting the ciphertext. N is a non-prime integer (preferably the product of two primes p and q), y is an element in multiplicative group of integers modulo N, and k is an integer larger than 1, Decryption of ciphertext c using private key is performed by recovering such that holds and outputting plaintext m, wherein denotes the 2k-th power residue symbol modulo p, which is defined. Also provided are an encryption device and a decryption device. The encryption scheme provides better bandwidth than the Goldwasser-Micali encryption scheme. | 08-01-2013 |
20130318624 | METHOD AND DEVICE FOR CONTROLLING DISTRIBUTION OF LICENSES - A method for controlling distribution of licenses, a license being for an excerpt of a content item, the content item comprising a set of continuous units, each excerpt comprising a subset of the set of continuous units, A device receives an identifier of a receiver of a license, and the license or a request to generate the license, the license or the request to generate the license comprising a content identifier and at least one indicator of the units covered by the license; retrieves stored information regarding licenses previously delivered to the receiver; compares a limit value for the content item with the stored information combined with information from the license or the request to generate the license; and allows the receiver access to the license only if the limit value is not exceeded by the stored information combined with information from the license or the request to generate the license Also provided is the device. | 11-28-2013 |
20140140504 | SYSTEM, DEVICES AND METHODS FOR COLLABORATIVE EXECUTION OF A SOFTWARE APPLICATION COMPRISING AT LEAST ONE ENCRYPTED INSTRUCTION - Collaborative execution by a first device and a second device of a software application comprising at least one encrypted instruction. The first device obtains a first encrypted instruction; generates a session key; encrypts the first encrypted instruction; encrypts the session key using a symmetric algorithm and a first key; and transfers the encrypted first encrypted instruction and the encrypted session key to the second device. The second device decrypts the encrypted session key using the first key; decrypts the encrypted first encrypted instruction to obtain the first encrypted instruction; decrypts the first encrypted instruction using a third key to obtain an instruction; encrypts the instruction using the symmetric encryption algorithm and the session key to obtain a second encrypted instruction; and transfers the second encrypted instruction to the first device. The first device decrypts the second encrypted instruction using the session key to obtain the instruction; and executes the instruction. | 05-22-2014 |
20140237253 | CRYPTOGRAPHIC DEVICES AND METHODS FOR GENERATING AND VERIFYING COMMITMENTS FROM LINEARLY HOMOMORPHIC SIGNATURES - A processor of a device generates a cryptographic commitment by receiving a vector {right arrow over (m)}, a public verification key of a homomorphic signature scheme, and a tag; choosing a signature σ in the signature space; generating a commitment c by running the verification algorithm of the homomorphic signature scheme; and outputting the commitment c as intermediate values resulting from the verification algorithm. | 08-21-2014 |
20140237254 | CRYPTOGRAPHIC DEVICES AND METHODS FOR GENERATING AND VERIFYING LINEARLY HOMOMORPHIC STRUCTURE-PRESERVING SIGNATURES - Generation of linearly homomorphic structure-preserving signature σ on a vector (M | 08-21-2014 |
20140270155 | METHOD AND A DEVICE FOR FAULT-RESISTANT EXPONENTIATION IN CRYPTOGRAPHIC SYSTEMS - A processor in a device performs fault-resistant exponentiation using an input x and a secret exponent d to obtain a result S, by using an a priori selected integer r and a chosen random element a ε {0, . . . , r−1} to form an extended base {circumflex over (x)} is formed such that | 09-18-2014 |
20140270156 | CRYPTOGRAPHIC DEVICES AND METHODS FOR ENCODING-FREE ENCRYPTION ON ELLIPTIC CURVES - Encoding-free encryption on elliptic curves is obtained by a device having a processor choosing an integer r∈ | 09-18-2014 |
20140321642 | GROUP ENCRYPTION METHODS AND DEVICES - The present invention improves on prior art group encryption schemes by encrypting an alias of a recipient's public key instead of the public key itself. A Group Manager publishes the encryption of the alias,the corresponding public key and a corresponding certificate on a public database DB. The alias is a resulting value of a suitably chosen function ƒ on the public key, and can be viewed as a hash of the public key. This can allow a significant decrease in the size and cost of the resulting construction as the alias can be made smaller than the public key. In particular, there is no need to apply the second encryption scheme as many times as there are group dements in the recipient's public key. | 10-30-2014 |
20150067340 | CRYPTOGRAPHIC GROUP SIGNATURE METHODS AND DEVICES - To generate a group signature on a message, a processor generates a two-level signature on an identity of the group member at the first level and the message at the second level; generates a commitment to the identity of the group member, commitments to each group element and a proof that the identity and the group elements satisfy a predetermined equation; encodes the identity of the group member in the group signature in a bit-wise manner using an identity-based encryption scheme where the message serves as the identity of the identity-based encryption scheme to produce a ciphertext; generates a first proof that the ciphertext encrypts the identity of the group member; generates a second proof that the encoded identity is an identity of a group member in a certificate signed by a group manager and that the certificate was used to generate the signature on the message at the second level; and outputs the group signature comprising the two-level signature, the commitments, the encoded identity of the group member and the proofs | 03-05-2015 |