116 results about "Cryptanalysis" patented technology

A dynamic computer communication security encryption method or system using an initial seed key and multiple random number generators of a specific design, whereby a sequence of independent random entropy values is produced by one set of random number generators and encrypted along with the message stream using the initial seed key, or the output of a second set of random number generators initialized with the initial seed key, and following the subsequent transmission of the variable encrypted entropy / message block, the entropy values are used to symmetrically or identically augment or increase the current uncertainty or entropy of the cryptosystem at both the sender and the receiver, prior to the next encryption block operation. The encryption process effectively entailing the use of multiple encryption ciphers, and the entropy augmentation process entailing the encryption or application of various logical mathematical operations on the already dynamic but deterministic internal state values of the second set of random number generators, effectively altering their deterministic outputs in a random probabilistic manner.Random length message value sequences from one or more data sources is combined with one or more random length entropy value sequences from an independent source, following which the entropy “updates” may also be used to alter, or change any cryptosystem variable, value or component in a randomly determined manner. In addition, whilst ensuring synchronization, the random entropy sequences also serve to “pollute” the cipher-stream and thereby hinder most current forms of cryptanalysis, whilst simultaneously injecting additional entropy into the cryptographic system and allowing for its propagation to affect any connected system nodes, and thereby introducing unpredictable entropy into the system pseudorandom number generator outputs, and thereby ensuring the perpetual generation of unpredictable random numbers.Super-encryption mechanics are independent of the user data, simple, fast and efficient, and can incorporate compression, error correction and asymmetric encryption authentication routines. But most importantly, super-encryption ensures resistance to brute force attacks (not possible to verify if a message was even sent), an ability to exceed “perfect secrecy” requirements, and an improvement on previous super-encipherment design, since overhead can be dramatically reduced from 100% overhead.Communication links previously established by system nodes with central authorities may be used for secure node authentication and registration, whilst allowing the central authority to broker and synchronize communication channels and providing mutual authentication and other security functions between the system nodes.

A block key to encrypt block data is generated using an ATS (arrival time stamp) appended to each of TS (transport stream) packets included in a transport stream correspondingly to the arrival time of the TS packet. The ATS is a random data depending upon an arrival time, and so a block-unique key can be generated, which enhances the protection against data cryptanalysis. A block key is generated from a combination of an ATS with a key unique to a device, recording medium or the like such as a master key, disc-unique key, title-unique key or the like. Since an ATS is used to generate a block key, any area for storage of an encryption key for each block may not be provided in a recording medium.

A system and method is provided for determining a risk associated with a login transaction. A password received during the login attempt and determination is made regarding whether the received password is derived form user information. A risk is determined based on a determination that the received password is derived from the user information.

A method for enhancing the security of cryptographic systems against side channel attacks and cryptanalysis is based on the concept of object hopping or dynamic transformation of elements between objects that share the same category and / or floating objects which facilitate object hopping. The use of floating objects and floating finite fields to facilitate field hopping is also disclosed. Further, the use of curve hopping and floating elliptic curves to facilitate curve hopping and / or key floating when keys used in cryptosystems are floated through floating fields are also used for enhancing the security of cryptographic systems.

According to the configuration of the present invention, the modulation clock signal is generated in accordance with a signal based on a random number, and a data processing timing is determined in accordance with the modulation clock signal to execute data processing. Accordingly, secret information analysis of an encryption key, a decryption key and the like through measurements of consumption powers in terms of a lapse time of a cryptographic processing apparatus for encrypting and decrypting data, i.e., cryptanalysis based on the power analysis, can be made difficult to thereby realize a cryptographic processing apparatus and method having a high security level.

The invention provides an identity authentication and key agreement method suitable for an electricity consumption information collection system. On the basis of a traditional identity authentication and key agreement method, a digital certificate identity identification mechanism, a signature authentication mechanism using an authoritative institution to inquire the validity of a digital certificate, and a challenge response mechanism based on a symmetric key are introduced to achieve the identity authentication and key agreement of a master station and terminals. The method can effectively resist attacks such as faking of the master station, communication service flow analysis, password analysis and the like, and enhances the safety of the electricity consumption information collection system.

An encrypting apparatus includes an encrypting operation section, a determining section and a control section. The encrypting operation section carries out an encrypting operation to a plaintext using intermediate data at each of a plurality of encrypting stages of the encrypting operation to produce a ciphertext. The encrypting operation section outputs encrypting stage data indicating an encrypting state at each of the plurality of processing stages. The determining section determines whether the encrypting operation at a next encrypting stage should be changed, based on the encrypting stage data at a current encrypting stage from the encrypting operation section. The control section changing the encrypting operation at the next encrypting stage when it is determined that the encrypting operation at the next encrypting stage should be changed.

The invention belongs to a novel encrypting method, in particular relates to a method for encrypting in sections by using an uncertain encryption algorithm. The method is used for encrypting the plain text in sections; and the algorithm for encrypting each section is uncertain and secret and determined by generalized keys. The method adopts the generalized keys to determine the length of each section, the encrypting algorithm of each section, various keys and parameters. Because the algorithm is uncertain, password analyzers do not know where to decrypt, though the analyzers get some information, the information means nothing to decrypt other sections.

A computer hardware implemented cryptography method computes a modular exponentiation, M:=Cd (mod p·q) upon a message data value C using a Chinese Remainder Theorem (CRT) based technique. To secure against cryptanalysis,, the private key moduli p and q are transformed by multiplication with a generated random value s, so that p′:=p·s and q′:=q·s. The CRT steps of the modular exponentiation are applied using the transformed moduli p′ and q′ to obtain a random intermediate message data value M′. A final reduction of M′ modulo p·q yields the final message data value M. Values needed for the computation are loaded into data storage and accessed as needed by electronic processing hardware.

A high-security cryptanalysis-resistant cryptographic processing apparatus and a cryptographic processing method are provided. A Feistel common key block cipher is produced by repeatedly performing an SPN-type F-function including a nonlinear transformation part and a linear transformation part over a plurality of rounds. In each round, a linear transformation process is performed according to an F-function using a matrix determined so as to satisfy a relatively loose constraint whereby high resistance to differential attacks and / or linear attacks is achieved. The relatively loose constraint allows an increase in the number of candidates for usable matrices, and it is possible to maintain the number of active S-boxes to a sufficiently large level. This makes it possible to increase the minimum number of active S-boxes, which is one of measures indicating the degree of robustness of ciphers, and thus it is possible to realize an algorithm of encrypting data in a highly secure manner so that high resistance to attacks is achieved.

The present encryption apparatus is provided with a plurality of conversion means connected in multiple steps, an intermediate-key generating means for performing linear or non-linear conversion for an intermediate-key and subsequently generating an initial-value of the intermediate-key, and an intermediate-key memory means for updating and storing the intermediate-key update information. The present encryption apparatus provides a ciphertext which is refractory to a chosen plaintext cryptanalysis in the evaluation of the key update information. The present apparatus is capable of high speed operation by parallel processing and is also capable of maintaining high speed operation by higher multiplication of the parallel operation even when the number of repetitive conversion is increased.

A data encryption system implemented by running on a cache-equipped computer an encryption program including transformation tables each of which contains a predetermined number of entries. All or necessary ones of the transformation tables are loaded into the cache memory before encryption / decryption process. This causes encryption / decryption time to be made substantially equal independently of the number of operation entries for the transformation table. It is very difficult to extract plain texts used to determine a key differential, resulting in difficulties in cryptanalysis.

The invention discloses a multiple uncertainty encryption system with a misleading function, which aims at attacks such as rubber-hose attacks, key stealing, brute force attacks and the like. Multiple encryption is performed, and an algorithm and encryption multiplicity are uncertain, so the system has multiple uncertainty, a password analyzer cannot perform analysis, and even though the brute force attacks are adopted, a plaintext obtained only by incomplete single decryption is meaningless. The encryption multiplicity of the algorithm, encryption algorithms of each layer and keys of each layer are all uncertain, and are all included in a structural master key. The multiple uncertainty makes securer the algorithm. The system is required to comprise an improved one-time pad mechanism, and one-time pad has high reversibility, so the encryption system can obtain pseudo keys in two ways to mislead and confuse the password analyzer, and has high value in military affairs and special occasions.

The invention relates to an information security technology in information technology field, which concretely relates to binary code and decode of data. The invention belongs to sequence coding system; the essence is periodless multi-table code substituting method. It uses dynamic length variable code technology, a group of input data with fixed length (8 bits), the length of the output code is between 1 and 255, the size of the encrypted text is determined according to the state of the coding system. The state of the system will change after coding a group of plain text, and the initial state of the system is determined by the user key, the code analyzer is hard to determine the relation between the encrypted text and the plain text, thus the attacking method to each kind of system can be resisted effectively.

Disclosed is the design and development of a new cipher called the Dragonfire Cipher. The Dragon cipher includes message authentication code and keyed random number generator. Dragonfire cipher takes this transparent method of generating S-boxes and uses them to create a cipher with keyed S-boxes. This defeats most precomputations for cryptanalysis as the S-boxes are now different between sessions.

The invention belongs to the field of information security and relates to construction of encryption algorithm. The password (encryption) algorithm is uncertain and random by using the random function to construct the block encryption method. The uncertainties are determined by partial data in the secret key and some information of plaintext. The encryption method has the advantage that the indeterminacy of the algorithm ensures that the password analysis becomes very difficult as a result of the lack of the information about the algorithm, so that a great amount of known (selected) plaintext ciphertext pair of the same algorithm and the same secret key cannot be acquired, and the condition for password analysis is destroyed to enhance the security. The existing abundant password analysis aims at determined algorithm, and the password analysis is difficult to perform when the algorithm is random. The uncertainty of the password system is increased through multiple ways. The encryption algorithm of the plaintext is uncertain, and the algorithms of different blocks are different, therefore, the secret key space can be increased so as to enhance the safety.

The invention relates to an encryption method with a misleading function, which is used for the stealing of keys, and the seizing, rubber-hose cryptanalysis and ciphertext only attacks to a key holder. When the encryption is performed by using the method disclosed by the invention, a false key can be obtained easily so as to mislead a password analyst, and the misleading is decided by an inner key, for carrying out any misleading, a sub-key is generated by using a long random sequence, and the long random sequence can be generated through quantum key distribution. Tags in a document are processed in a special processing mode, so that even a specified tag appears in a text, a confusion phenomenon does not occur. In the process of encryption, a key word database is required, so that in the process of inner encryption, the expansion on key words is performed by using the database, and the outer encryption is performed by using the conventional encryption method. In the method, in the process of decryption, the support of the database is not required, thereby avoiding the occurrence of a database synchronization problem. The method disclosed by the invention has a certain application value in encryption applications in various occasions, especially in the military field.

The invention provides a dynamic encrypt system based on a generalized information field, which comprises a pseudo-random code generator based on the generalized information field and an encryption and decryption subsystem, wherein the pseudo-random code generator is connected with the encryption and decryption subsystem, and the encryption and decryption subsystem comprises an encryption subsystem and a decryption subsystem. The pseudo-random code generator based on the generalized information field comprises an initial address message IV generating module, an IV normalized module, an m module, a constrained processing module and a key length judgment module which are connected in sequence, wherein the m module is connected with an activity background generating module, and the activity background generating module comprises a physical reconstruction module and a logical reconstruction module. The encryption subsystem and the decryption subsystem both comprise grouping coefficient and round key generating modules, grouping modules, position interchange modules and substitution operation modules. The invention introduces the generalized information field, and realizes the key safety to transfer towards the generalized information field safety; the cryptanalysis resistance is strong.

In an unsafe environment, a cryptographic analyzer can implement attacks on an algorithm and a secret key by tracking a binary system operated by a program, reading the secret key in a memory and a program execution intermediate result, carrying out static analysis and the like, and a white-box cryptographic algorithm can protect the secret key in the unsafe environment. The invention discloses a 16-round SM4-128 / 128 white box password implementation method, which describes a new mode of improving an SM4 password algorithm when the encryption round number is 16, and the mode improves the structure of a round function, namely the iterative process of the encryption algorithm. An improved SM4 white-box cryptographic algorithm is provided, and the whole encryption and decryption process can be converted into a form of calculating randomly selected affine transformation and lookup tables. The principle is that the internal state of a coding hiding algorithm is input and output scrambled, the secret key is embedded into a lookup table in a coding mode, and meanwhile, a block matrix is used for reducing the scale of the lookup table.

The invention provides a dynamic deficiency encryption system. The system is characterized in that ciphertext data transferred during communication randomly loses part of valid data and is rearranged, so that information is not complete, ciphertext can not be directly conducted to cryptanalysis and cracking, interception is prevented, and secure communication channels are reinforce. The system adopting verification codes can find lost ciphertext through multiple trial operation, further performs decryption recovery to complete ciphertext. The invention also discloses a high-security protection reinforcement system adopting dynamic deficiency, identification certification, environment locking, periodical activation and random scrambling.

In order to further develop a circuit arrangement ( 100 ), in particular an integrated circuit, for electronic data processing as well as a method for detecting and / or for registering and / or for signaling the irradiation of at least one non-volatile memory module ( 10 ) with at least one light source in order to be capable of securely averting an attack, in particular an E[lectro]M[agnetic] radiation attack, for example a side-channel attack, or in particular a crypto-analysis, for example a current trace analysis or a D[ifferential]P[ower]A[nalysis], such attack or such analysis in particular being targeted on finding out a private key, it is proposed that an access timing for at least one read access to the memory module ( 10 ) is generated, in particular that at least one additional read access to the memory module ( 10 ) is added in at least one test mode (T), in particular in at least one D[isable]A[ll]W[ordline] mode, this test mode (T) preferably allowing to detect if the memory module ( 10 ) is currently exposed to any light of a certain energy.

Aiming at various attacks possibly existing in reality, the invention discloses an encryption method with a misleading function. A pseudo key can be easily obtained after using the encryption method, thus, a cryptanalyst can be misled, the misleading is dependent on an inlayer key, for performing any misleading, a sub-key is generated by long random sequences, and the long random sequences can be generated by quantum key distribution. For saving keys, the shortest key length is intercepted as needed, in decryption, corresponding information is obtained, and the key length intercepted in encryption also can be determined so as to keep synchronous. A keyword database is needed for encryption, keyword expansion for inlayer encryption of the encryption process is executed based on the database, and the outer layer encryption uses a conventional encryption method. The method has certain use value in the encryption in various occasions, particularly in the aspect of military affairs.

The invention discloses an encryption method with a misguiding function, aiming at attacks such as secret key stealing, secret key holder seizing, rubber-hose cryptanalysis, ciphertext-only attack and the like. A pseudo secret key can be easily obtained through encryption with the method disclosed by the invention, thus a password analyzer can be misguided, the misguiding is determined by an internal secret key and comprises information for generating a secret key flow and correction information, and the misguiding effectiveness can be enhanced according to actual demands by using the correction information. For a special processing mode adopted by signs in a document, the specified signs can not be confused when possibly occurring in a text. A keyword database is needed during encrypting, internal encryption is subjected to keyword expansion by using the database, and the traditional encryption method is adopted in external encryption. The invention does not need the support of the database during encrypting so as to avoid the problem of synchronization of the database. The invention has a certain use value in the encryption application of various occasions, especially military.

A method, computer program product, and data processing system for generating and validating an upgradeable digital timestamp of a document is disclosed. The digital timestamp includes a hash value, a current time, and a digital signature. Over time, as computer and cryptanalytic technology progresses, upgrade timestamps are applied to the document that take advantage of more advanced, more difficult to break hash functions or digital signature schemes. These upgrade timestamps are applied preventatively at a point in time just prior to the timestamp's being able to be compromised.

The invention discloses a searching method for an impossible differential path of a related key of a block cipher. As an impossible differential attack method and a related key attack method are combined, the problems of automatic searching of the impossible differential path of the related key and searching of a longest analysis path in cryptanalysis are solved, and deeper and more thorough analysis for a cryptographic algorithm can be carried out. According to the searching method for the impossible differential path of the related key of the block cipher, the method for searching the impossible differential path of the related key is upgraded from the traditional manual analysis to computer automatic searching, the disadvantages that an existing manual analysis method is fussy and error-prone when being used for analyzing the cryptographic algorithm are avoided, the maximum length of the impossible differential path of the related key of the block cipher algorithm can be calculated rapidly and accurately, and the cryptanalysis efficiency is improved. The searching method for the impossible differential path of the related key of the block cipher realizes transformation of the cryptographic algorithm from a non-generalized Feistel structure to a generalized Feistel structure, can be widely applied to automatic search of the impossible differential paths of related keys of various cryptographic algorithms in different structures.