摘要:
In a Digital Rights Management (DRM) system, cryptographic keys for decrypting distributed assets (such as audio or video media) are distributed using an offline (e.g., non-Internet) method for distribution of the key generation process, with an implicit authorization to use the distributed key generation process. This is used to update an asset key for use by a client such as a media player when a key formula for generating the key for decrypting an asset has been compromised, such as by hackers.
摘要:
Systems and methods for an implementation of block cipher algorithms (e.g., AES) use lookup tables to obscure key information, increasing difficulty of reverse engineering efforts. The implementation encodes round key information into a first plurality of tables (T1), which when used for lookup operations also complete SubBytes operations, and output state in an encoded format. A Shiftrows operation is performed arithmetically on the output state. A second plurality of tables (T2) are used to perform a polynomial multiplication portion of MixColumns operation, and an XOR portion of MixColumns is performed arithmetically on the columns. Encoding from the T1 tables is made to match a decoding built into the T2 tables. Subsets of the T1 tables use the same T2 tables, reducing a memory footprint for the T2 tables. Multiple AES keys can be embedded in different sets of T1 tables that encode for the same set of T2 tables.
摘要:
In the data security field, a data protection process embodied in a computer system or computing device or equivalent and which securely descrambles protected (scrambled) data. The process descrambles the data using a dynamic process employing a set of multi-level trees of deterministic functions to generate a descrambling mask value and recover the descrambled message.
摘要:
In the context of a computer client-server architecture, typically used in the Internet for communicating between a server and applications running on user computers (clients), a method is provided for enhancing security in the context of digital rights management (DRM) where the server is an untrusted server that may not be secure, but the client is secure. This method operates to authenticate the server to the client and vice versa to defeat hacking attacks intended to obtain confidential information. Values passed between the server and the client include encrypted random numbers, authentication values and other verification data generated using cryptographic techniques including double encryption.
摘要:
Disclosed herein are systems, methods, and non-transitory computer-readable storage media for executing encrypted computer code. A system configured to practice the method receives a request to execute encrypted computer code. In response to the request, the system identifies a portion of the encrypted computer code for execution and decrypts the portion to yield decrypted computer code. Then the system stores the decrypted computer code in a pool of memory and executes the decrypted computer code from the pool of memory. The system can store the decrypted computer code in the pool of memory based on a randomization algorithm so that identical executions of the encrypted computer code result in selections of different available memory locations within the pool of memory. Related portions can be stored non-consecutively in the pool of memory. The pool of memory can store different portions of decrypted computer code over time.
摘要:
Method and apparatus for obfuscating computer software code, to protect against reverse-engineering of the code. The obfuscation here is of the part of the code that performs a Boolean logic operation such as an exclusive OR on two (or more) data variables. In the obfuscated code, each of the two variables is first modified by applying to it a function which deconstructs the value of each of the variables, and then the exclusive OR operation is replaced by an arithmetic operation such as addition, subtraction, or multiplication, which is performed on the two deconstructed variables. The non-obfuscated result is recovered by applying a third function to the value generated by the arithmetic operation. This obfuscation is typically carried out by suitably annotating (modifying) the original source code.
摘要:
First source code of a computer program having a plurality of lines of instructions is received. An obfuscation process is performed on the first source code, including at least two of a shuffling operation, a fertilizing operation, an aggregating operation, and a neutralizing operation. Second source code is generated based on the obfuscation process, where the second source code, when executed by a processor, produces an identical result as the first source code.
摘要:
An asymmetric (dual key) data obfuscation process, based on the well known ElGamal cryptosystem algorithm, and which uses multiplicative cyclic groups to transform (obfuscate) digital data for security purposes. In the present system the data need not be a member of the cyclic group, unlike in the ElGamal cryptosystem algorithm. Also, any one of several additional mathematical data transformations are further applied to the transformed data, thereby enhancing security of the transformed data.
摘要:
A method and an apparatus that generate a plurality of elements randomly as a split representation of an input used to provide an output data cryptographically representing an input data are described. The input may correspond to a result of a combination operation on the elements. Cryptographic operations may be performed on the input data and the elements to generate a plurality of data elements without providing data correlated with the key. The combination operation may be performed on the data elements for the output data.
摘要:
First source code of a computer program having a plurality of lines of instructions is received. An obfuscation process is performed on the first source code, including at least two of a shuffling operation, a fertilizing operation, an aggregating operation, and a neutralizing operation. Second source code is generated based on the obfuscation process, where the second source code, when executed by a processor, produces an identical result as the first source code.