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Post-Quantum Extended Diffie–Hellman
In cryptography, Post-Quantum Extended Diffie–Hellman (PQXDH) is a Kyber-based post-quantum cryptography upgrade to the Diffie–Hellman key exchange. It is notably being incorporated into the Signal Protocol, an end-to-end encryption protocol. In September 2023, the developers of the Signal Protocol announced that it was being updated to support PQXDH. PQXDH is an upgraded version of the X3DH protocol and uses both the quantum-resistant CRYSTALS-Kyber protocol as well as the old elliptic curve X25519 protocol. This ensures that an attacker must break both of the encryption protocols to gain access to sensitive data, mitigating potential security vulnerabilities the new protocol could have. The protocol is designed for asynchronous communication where the clients exchange public keys through a server to derive a secure shared key which they can use to encrypt sensitive data without needing to constantly sync new keys with each other. In October 2023, the protocol underwen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptography
Cryptography, or cryptology (from "hidden, secret"; and ''graphein'', "to write", or ''-logy, -logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of Adversary (cryptography), adversarial behavior. More generally, cryptography is about constructing and analyzing Communication protocol, protocols that prevent third parties or the public from reading private messages. Modern cryptography exists at the intersection of the disciplines of mathematics, computer science, information security, electrical engineering, digital signal processing, physics, and others. Core concepts related to information security (confidentiality, data confidentiality, data integrity, authentication, and non-repudiation) are also central to cryptography. Practical applications of cryptography include electronic commerce, Smart card#EMV, chip-based payment cards, digital currencies, password, computer passwords, and military communications. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Server (computing)
A server is a computer that provides information to other computers called " clients" on a computer network. This architecture is called the client–server model. Servers can provide various functionalities, often called "services", such as sharing data or resources among multiple clients or performing computations for a client. A single server can serve multiple clients, and a single client can use multiple servers. A client process may run on the same device or may connect over a network to a server on a different device. Typical servers are database servers, file servers, mail servers, print servers, web servers, game servers, and application servers. Client–server systems are usually most frequently implemented by (and often identified with) the request–response model: a client sends a request to the server, which performs some action and sends a response back to the client, typically with a result or acknowledgment. Designating a computer as "server-class hardwa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
End-to-end Encryption
End-to-end encryption (E2EE) is a method of implementing a secure communication system where only communicating users can participate. No one else, including the system provider, telecom providers, Internet providers or malicious actors, can access the cryptographic keys needed to read or send messages. End-to-end encryption prevents data from being read or secretly modified, except by the true sender and intended recipients. Frequently, the messages are relayed from the sender to the recipients by a service provider. However, messages are encrypted by the sender and no third party, including the service provider, has the means to decrypt them. The recipients retrieve the encrypted messages and decrypt them independently. Since third parties cannot decrypt the data being communicated or stored, services that provide end-to-end encryption are better at protecting user data when they are affected by data breaches. Such services are also unable to share user data with governm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal (software)
Signal is an American open-source, encrypted messaging service for instant messaging, voice calls, and video calls. The instant messaging function includes sending text, voice notes, images, videos, and other files. Communication may be one-to-one between users or may involve group messaging. The application uses a centralized computing architecture and is cross-platform software. It is developed by the non-profit Signal Foundation and its subsidiary Signal Messenger LLC. Signal's software is free and open-source. Its mobile clients, desktop client, and server are all published under the AGPL-3.0-only license. The official Android app generally uses the proprietary Google Play Services, although it is designed to be able to work without them. Signal is also distributed for iOS and desktop programs for Windows, macOS, and Linux. Registration for desktop use requires an iOS or Android device. Signal uses mobile telephone numbers to register and manage user accounts, thoug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shor's Algorithm
Shor's algorithm is a quantum algorithm for finding the prime factors of an integer. It was developed in 1994 by the American mathematician Peter Shor. It is one of the few known quantum algorithms with compelling potential applications and strong evidence of superpolynomial speedup compared to best known classical (non-quantum) algorithms. On the other hand, factoring numbers of practical significance requires far more qubits than available in the near future. Another concern is that noise in quantum circuits may undermine results, requiring additional qubits for quantum error correction. Shor proposed multiple similar algorithms for solving the factoring problem, the discrete logarithm problem, and the period-finding problem. "Shor's algorithm" usually refers to the factoring algorithm, but may refer to any of the three algorithms. The discrete logarithm algorithm and the factoring algorithm are instances of the period-finding algorithm, and all three are instances of the h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Post-quantum Cryptography
Post-quantum cryptography (PQC), sometimes referred to as quantum-proof, quantum-safe, or quantum-resistant, is the development of cryptographic algorithms (usually public-key algorithms) that are currently thought to be secure against a cryptanalytic attack by a quantum computer. Most widely-used public-key algorithms rely on the difficulty of one of three mathematical problems: the integer factorization problem, the discrete logarithm problem or the elliptic-curve discrete logarithm problem. All of these problems could be easily solved on a sufficiently powerful quantum computer running Shor's algorithm or possibly alternatives. As of 2024, quantum computers lack the processing power to break widely used cryptographic algorithms; however, because of the length of time required for migration to quantum-safe cryptography, cryptographers are already designing new algorithms to prepare for Y2Q or Q-Day, the day when current algorithms will be vulnerable to quantum computin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formal Verification
In the context of hardware and software systems, formal verification is the act of proving or disproving the correctness of a system with respect to a certain formal specification or property, using formal methods of mathematics. Formal verification is a key incentive for formal specification of systems, and is at the core of formal methods. It represents an important dimension of analysis and verification in electronic design automation and is one approach to software verification. The use of formal verification enables the highest Evaluation Assurance Level ( EAL7) in the framework of common criteria for computer security certification. Formal verification can be helpful in proving the correctness of systems such as: cryptographic protocols, combinational circuits, digital circuits with internal memory, and software expressed as source code in a programming language. Prominent examples of verified software systems include the CompCert verified C compiler and the seL ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symmetric-key Algorithm
Symmetric-key algorithms are algorithms for cryptography that use the same cryptographic keys for both the encryption of plaintext and the decryption of ciphertext. The keys may be identical, or there may be a simple transformation to go between the two keys. The keys, in practice, represent a shared secret between two or more parties that can be used to maintain a private information link. The requirement that both parties have access to the secret key is one of the main drawbacks of symmetric-key encryption, in comparison to public-key encryption (also known as asymmetric-key encryption). However, symmetric-key encryption algorithms are usually better for bulk encryption. With exception of the one-time pad they have a smaller key size, which means less storage space and faster transmission. Due to this, asymmetric-key encryption is often used to exchange the secret key for symmetric-key encryption. Types Symmetric-key encryption can use either stream ciphers or block ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Public-key Cryptography
Public-key cryptography, or asymmetric cryptography, is the field of cryptographic systems that use pairs of related keys. Each key pair consists of a public key and a corresponding private key. Key pairs are generated with cryptographic algorithms based on mathematical problems termed one-way functions. Security of public-key cryptography depends on keeping the private key secret; the public key can be openly distributed without compromising security. There are many kinds of public-key cryptosystems, with different security goals, including digital signature, Diffie–Hellman key exchange, Key encapsulation mechanism, public-key key encapsulation, and public-key encryption. Public key algorithms are fundamental security primitives in modern cryptosystems, including applications and protocols that offer assurance of the confidentiality and authenticity of electronic communications and data storage. They underpin numerous Internet standards, such as Transport Layer Security, T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kyber
Kyber is a key encapsulation mechanism (KEM) designed to be resistant to cryptanalysis, cryptanalytic attacks with future powerful quantum computing, quantum computers. It is used to establish a shared secret between two communicating parties without an (IND-CCA2) attacker in the transmission system being able to decrypt it. This public-key cryptography, asymmetric cryptosystem uses a variant of the learning with errors lattice problem as its basic trapdoor function. It won the NIST Post-Quantum Cryptography Standardization, NIST competition for the first post-quantum cryptography (PQ) standard. NIST calls its standard, numbered FIPS 203, Module-Lattice-Based Key-Encapsulation Mechanism (ML-KEM). Properties The system is based on the module learning with errors (M-LWE) problem, in conjunction with cyclotomic field, cyclotomic Ring (mathematics), rings. Recently, there has also been a tight formal mathematical security reduction (mathematics), reduction of the ring-LWE problem to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X25519
X, or x, is the twenty-fourth letter of the Latin alphabet, used in the English alphabet, modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is Wikt:ex#English, ''ex'' (pronounced ), plural ''exes''."X", ''Oxford English Dictionary'', 2nd edition (1989); ''Merriam-Webster's Third New International Dictionary of the English Language, Unabridged'' (1993); "ex", ''op. cit''. History The letter , representing , was inherited from the Etruscan alphabet. It perhaps originated in the of the Archaic Greek alphabets#Euboean, Euboean alphabet or another Western Greek alphabet, which also represented . Its relationship with the of the Eastern Greek alphabets, which represented , is uncertain. The pronunciation of in the Romance languages underwent Palatalization in the Romance languages, sound changes, with various outcomes: * French language, French: (e.g. ''laisser'' from ''laxare'') * Italian language, Itali ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
