A data processing method and apparatus based on a blockchain network, and a computer device. The method includes acquiring a transaction request, the transaction request carrying transaction data and reference signature data corresponding to the transaction data; validating the transaction data and the reference signature data; determining a matching node device from a target node device if the transaction data and the reference signature data are validated, and acquiring a signing key of the matching node device; determining data to be signed according to the transaction data, and signing on the data to be signed using the signing key of the matching node device to obtain endorsement signature data; and transmitting the endorsement signature data to the management device, wherein the management device generates a transaction block according to the endorsement signature data and the transaction data.

An electronic watermark embedding apparatus according to an embodiment is an electronic watermark embedding apparatus capable of embedding an electronic watermark into a decoding circuit of secret-key encryption, and includes an embedding unit configured to generate the decoding circuit. The decoding circuit is embedded with the electronic watermark by being input with a common parameter generated in a setup of the secret-key encryption, a secret key of the secret-key encryption, and the electronic watermark, and is capable of decoding an encrypted text encrypted using the secret-key encryption.

Disclosed is a method for a secure communication method having a secret key generation technique. The novelty of the proposed method stems from enhancing physical layer security (PHY) by using channel-adaptive keys, after manipulating a channel by introducing an artificial component into the channel. An adaptively designed artificial component is cascaded with the legitimate user’s channel. In an orthogonal frequency division multiplexing (OFDM) system, subcarriers corresponding to a channel gain higher than a threshold value are selected to extract the keys. Since the number of the selected subcarriers is adaptive, the length of the generated key sequences is changing adaptively as well. Thus, the channel reciprocity property in a time division duplexing (TDD) system is utilized.

Disclosed are a confirmation system and method which enables confirmation of the users of the application/device owners without using SMS in an easy manner.

A server determines an array [[addr]] indicating a storage destination of each piece of data, generates an array of concealed values, and connects the generated array to the array [[addr]] to determine an array [[addr′]]. The server generates a sort permutation [[σ.sub.1]] for the array, applies the sort permutation [[σ.sub.1]] to the array [[addr′]], and converts the array [[addr′]] into an array with a sequence composed of first Z elements set to [[i]] followed by α.sub.i elements set to [[B]]. The server generates a sort permutation [[σ.sub.2]] for the converted array [[addr′]], generates dummy data, imparts the generated dummy data to the concealed data sequence, applies the sort permutations [[σ.sub.1]] and [[σ.sub.2]] to the data array imparted with the dummy data, and generates, as a secret hash table, a data sequence obtained by deleting the last N pieces of data from the sorted data array.

Methods for communicating messages encoded in quantum objects comprise exchanging series of values on a classical communication channel between quantum communication devices. Basically, one of the quantum devices discloses a clue on its intention to use a polarization basis for a given quantum object while the other device discloses clue on a basis it will not use in a way similar to the Monty Hall Problem.

A cryptographic system includes an encryption apparatus including a memory and a processor configured to encrypt a plaintext into a ciphertext. The processor of the encryption apparatus executes generating first information resulting from encryption of the plaintext by an encryption function of a predetermined block cipher using a first secret key; generating second information resulting from encryption of a preset adjustment value by the encryption function using a second secret key; and generating the ciphertext by encrypting an arithmetic operation result of a bitwise exclusive OR of the first information and the second information by the encryption function using the first secret key.

A flag sequence generator (12) generates {x.sub.0}, . . . , {x.sub.λ−11} indicating a msb of a. A bit sequence generator (13) calculates {y.sub.i}:={x.sub.2i} XOR {x.sub.2i+1} to generate {y.sub.0}, . . . , {y.sub.λ′−1}. A flag calculator (14) calculates an exclusive logical sum of all {x.sub.j} to calculate [r] for each odd j. A public value multiplier setting-unit (16) sets r′ that becomes √2 when λ is an odd and 1 when λ is an even. A normalization multiplier generator (17) bit-connects {y.sub.0}, . . . to generate [c′]. A normalization multiplier generator (18) bit-connects {x.sub.λ−1}, . . . to generate [c]. A normalizer (19) calculates [b]:=[a][c]. A square root calculator (20) calculates [w]:=[√b]*(r′/√2) when r=1, and [w′]:=[√b]*r′ when r=0. An inverse normalizer (21) calculates [w][c′] and performs λ′ bits right-shift.

A communication apparatus establishes, in a case where a second radio link is established with a partner apparatus in communication in addition to an already established first radio link, the second radio link using information obtained by authentication processing executed at the time of establishing the first radio link.

Various techniques are provided to implement information leakage mitigation associated with elliptic curve operations. In one example, a method includes generating second data based on first data. The first data is associated with a message. The second data is associated with a decoy message. The method further includes performing a first elliptic curve operation based on the first data. The method further includes performing a second elliptic curve operation based on the second data. The first elliptic curve operation and the second elliptic curve operation are performed in a random order. Related systems and devices are provided.