A method for determining a cryptographic key is carried out in a data processing system, and comprises: providing a plaintext and a ciphertext determined from the plaintext using a cryptographic key and a cryptographic procedure which comprises cryptographic operations; for each cryptographic operation of the cryptographic procedure, providing at least one intermediate relation which comprises an intermediate equation and/or an intermediate inequality; determining an optimization problem comprising: the plaintext and the ciphertext; at least one optimization expression assigned to a round of the cryptographic procedure; and optimization variables comprising state variables of the cryptographic procedure and a cryptographic key variable; wherein the at least one optimization expression is determined from the at least one intermediate relation and comprises at least one preceding state variable assigned to a preceding round. The method further comprises: solving the optimization problem and determining the cryptographic key from an optimizing value of the cryptographic key variable.

Methods for quantum key distribution are disclosed including forming a quantum production key package with a production file name; forming a first quantum sacrificial key package with a first sacrificial file name associated with a portion of the first production file name; sending the quantum sacrificial key package to a sacrificial key server; and sending the quantum production key package to computer devices to set up a quantum key encryption tunnel between the computer devices. The quantum production key packages are received by computer devices that send the production file name to the sacrificial key server to receive the sacrificial return key. The sacrificial return key is used to decrypt the quantum production key package with the quantum production keys. A first quantum production key is retrieved to encrypt and decrypt data at each computer device.

The present invention relates to methods for secure computation and/or communication. Entangled photons (118) are generated such that each participating party receives a series of optical pulses. Each party has private information (110, 112) which are never transmitted through public or private communication channels. Instead, each party converts their respective private information (110, 112) into measurement bases via an encryption process (114, 116) which are then applied to the entangled photons (118). After the measurement process, e.g., quantum frequency conversion (122, 124), reference indices are announced (124, 126) so that computation can be performed (128) without revealing the private information directly or indirectly.

A method and system for encrypted messaging includes first and second client devices and a quantum key device having a quantum random number generator. The generator provides a first quantum random signal, and the key device provides a symmetric first master key from the first quantum random signal. The master key is transmitted to the first client device and stored. The key device uses the master key to generate an encrypted package by encrypting one of a plurality of keys. The key device generates a second encrypted package. The first pairing key is provided to the first client device by decrypting the first encrypted package using the first master key and providing the first pairing key in the second client device by decrypting the second encrypted package using the second master key to establish an encrypted connection between the first and second client devices.

Disclosed is a data encryption method performed by an apparatus, which includes encrypting plaintext data based on an encryption key to generate first ciphertext data, applying a noise vector being periodically extracted to an artificial intelligence-based generative model to generate a first signature code and a second signature code, and applying the first signature code and the second signature code to the first ciphertext data to generate second ciphertext data. The generating of the first signature code includes determining a type and a replacement location of a character necessary to generate the first signature code by means of a predetermined conversion formula and generating a first character, which is obtained by calculating an existing encryption character being present at the replacement location in the first ciphertext data and the character in a predetermined scheme, as the first signature code.

A device may include a processor configured to obtain a quantum key generated using quantum random numbers received from a quantum random number generator. The processor may be further configured to obtain a digital signature for a uniform resource locator (URL) associated with the obtained quantum key, wherein the digital signature is received from a security device configured to provide the quantum key to a user equipment (UE) device; receive a request from an application server to function as a proxy for a secure session with the UE device; authenticate the secure session with the UE device using the quantum key and the digital signature; and proxy the secure session between the UE device and the application server.

A system uses a keyboard application to encrypt and decrypt e-mail, messages, and other digital data. By using quantum random number generators, the system has improved data security. Using a quantum random number, an agent (at a sender side) generates an encryption key which is used to automatically encrypt a message. The encryption key is stored at a key server. The encrypted message will be sent by an application using its standard transmission means such as SMTP, SMS, and others. The encrypted message can be automatically unencrypted by using an agent (at a recipient side) and retrieving the key from the key server. The system also provides an optional double encryption, where the message is encrypted with a user-generated password before being encrypted using the encryption key.

Method(s), system(s), apparatus are provided for storing one or more data item(s) in a quantum-safe (QS) network. The QS network comprising one or more QS server(s) and a repository for storing and accessing said data item(s). Each QS server comprising a hardware security module (HSM) for storing an identical set of quantum distributed (QD) keys. The identical set of QD keys having been distributed to each of said QS server(s) in a quantum-safe manner. The QS server(s) are configured to communicate securely with each other and the repository using one or more available QD keys from the identical set of QD keys. A QS server performs generating a quantum reference (QREF) locator based on input data associated with a data item for storage and an available QD key selected from the set of QD keys, and sending the QREF locator along with the data item encrypted with the available QD key to the repository for storage.

Systems, devices, software, and methods of the present invention provide for homomorphically encrypted (HE) and other data represented as polynomials of degree K−1 to be transformed in O(K*log(K)) time into ‘unique-spiral’ representations in which both linear-time (O(K)) addition and linear-time multiplication are supported without requiring an intervening transformation. This capability has never previously been available and enables very significant efficiency improvements, i.e., reduced runtimes, for applications such as Fully Homomorphic Encryption (FHE), Post-Quantum Cryptography (PQC) and Artificial Intelligence (AI). Other efficient operations, such as polynomial division, raising to a power, integration, differentiation and parameter-shifting are also possible using the unique-spiral representations. New methods are introduced based on the unique-spiral representation that have applications to efficient polynomial composition, inversion, and other important topics.

A public-key scheme of Homomorphic Encryption (HE) in the framework Quotient Algebra Partition (QAP) comprises: encryption, computation and decryption. With the data receiver choosing a partition or a QAP, [n, k, C], a public key Key.sub.pub=(VQ.sub.en, Gen.sub.ε) and a private key Key.sub.priv=.sup.†P.sup.† are produced, where VQ.sub.en is the product of an n-qubit permutation V and an n-qubit encoding operator Q.sub.en, Gen.sub.ε an error generator randomly provides a dressed operator Ē=V.sup.†EV spinor error E of [n, k, C]. Then, by Key.sub.pub, the sender can encode his k-qubit plaintext Ix) into an n-qubit ciphertext |ψ.sub.en, which is transmitted to the cloud. The receiver prepares the instruction of encoded computation U.sub.en=PV.sup.†Q.sub.en.sup.† for a given k-qubit action M and sends to cloud, where is the error-correction operator of [n, k, C], =I.sub.2.sub.n−k.Math.M the tensor product of the (n−k)-qubit identity I.sub.2.sub.n−k and M , and V.sup.†Q.sup.†.sub.en and P the complex-transposes of VQ.sub.en and