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Key Wrap
In cryptography, key wrap constructions are a class of symmetric encryption algorithms designed to encapsulate (encrypt) cryptographic key material. The Key Wrap algorithms are intended for applications such as protecting keys while in untrusted storage or transmitting keys over untrusted communications networks. The constructions are typically built from standard primitives such as block ciphers and cryptographic hash functions. Key Wrap may be considered as a form of key encapsulation algorithm, although it should not be confused with the more commonly known ''asymmetric'' (public-key) key encapsulation algorithms (e.g., PSEC-KEM). Key Wrap algorithms can be used in a similar application: to securely transport a session key by encrypting it under a long-term encryption key. Background In the late 1990s, the National Institute of Standards and Technology (NIST) posed the "Key Wrap" problem: to develop secure and efficient cipher-based key encryption algorithms. The result ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Key Encapsulation Mechanism
In cryptography, a key encapsulation mechanism (KEM) is a public-key cryptosystem that allows a sender to generate a short secret key and transmit it to a receiver securely, in spite of eavesdropping and intercepting adversaries. Modern standards for public-key encryption of arbitrary messages are usually based on KEMs. A KEM allows a sender who knows a public key to simultaneously generate a short random secret key and an encapsulation or ciphertext of the secret key by the KEM's encapsulation algorithm. The receiver who knows the private key corresponding to the public key can recover the same random secret key from the encapsulation by the KEM's decapsulation algorithm. The security goal of a KEM is to prevent anyone who ''does not'' know the private key from recovering any information about the encapsulated secret keys, even after eavesdropping or submitting other encapsulations to the receiver to study how the receiver reacts. Difference from public-key encryption The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triple DES
In cryptography, Triple DES (3DES or TDES), officially the Triple Data Encryption Algorithm (TDEA or Triple DEA), is a symmetric-key block cipher, which applies the DES cipher algorithm three times to each data block. The 56-bit key of the Data Encryption Standard (DES) is no longer considered adequate in the face of modern cryptanalytic techniques and supercomputing power; Triple DES increases the effective security to 112 bits. A CVE released in 2016, CVE-2016-2183', disclosed a major security vulnerability in the DES and 3DES encryption algorithms. This CVE, combined with the inadequate key size of 3DES, led to NIST deprecating 3DES in 2019 and disallowing all uses (except processing already encrypted data) by the end of 2023. It has been replaced with the more secure, more robust AES. While US government and industry standards abbreviate the algorithm's name as TDES (Triple DES) and TDEA (Triple Data Encryption Algorithm), RFC 1851 referred to it as 3DES from the tim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Offline Private Key Protocol
The Offline Private Key Protocol (OPKP) is a cryptographic protocol to prevent unauthorized access to back up or archive data. The protocol results in a public key that can be used to encrypt data and an offline private key that can later be used to decrypt that data. The protocol is based on three rules regarding the key. An offline private key should: * not be stored with the encrypted data (obviously) * not be kept by the organization that physically stores the encrypted data, to ensure privacy * not be stored at the same system as the original data, to avoid the possibility that theft of only the private key would give access to all data at the storage provider; and to avoid that when the key would be needed to restore a backup, the key would be lost together with the data loss that made the restore necessary in the first place To comply with these rules, the offline private key protocol uses a method of asymmetric key wrapping. Security As the protocol does not provide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Key Management
Key management refers to management of Key (cryptography), cryptographic keys in a cryptosystem. This includes dealing with the generation, exchange, storage, use, crypto-shredding (destruction) and replacement of keys. It includes cryptographic protocol design, Key server (cryptographic), key servers, user procedures, and other relevant protocols. Key management concerns keys at the user level, either between users or systems. This is in contrast to key scheduling, which typically refers to the internal handling of keys within the operation of a cipher. Successful key management is critical to the security of a cryptosystem. It is the more challenging side of cryptography in a sense that it involves aspects of social engineering such as system policy, user training, organizational and departmental interactions, and coordination between all of these elements, in contrast to pure mathematical practices that can be automated. Types of keys Cryptographic systems may use different ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deterministic Encryption
A deterministic encryption scheme (as opposed to a probabilistic encryption scheme) is a cryptosystem which always produces the same ciphertext for a given plaintext and encryption key, key, even over separate executions of the encryption algorithm. Examples of deterministic encryption algorithms include RSA (algorithm), RSA cryptosystem (without encryption padding), and many block ciphers when used in electronic codebook, ECB mode or with a constant initialization vector. Leakage Deterministic encryption can leak information to an eavesdropper, who may recognize known ciphertexts. For example, when an adversary learns that a given ciphertext corresponds to some interesting message, they can learn something every time that ciphertext is transmitted. To gain information about the meaning of various ciphertexts, an adversary might perform a statistical analysis of messages transmitted over an encrypted channel, or attempt to correlate ciphertexts with observed actions (e.g., no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Authenticated Encryption
Authenticated Encryption (AE) is an encryption scheme which simultaneously assures the data confidentiality (also known as privacy: the encrypted message is impossible to understand without the knowledge of a secret key) and authenticity (in other words, it is unforgeable: the encrypted message includes an authentication tag that the sender can calculate only while possessing the secret key). Examples of encryption modes that provide AE are GCM, CCM. Many (but not all) AE schemes allow the message to contain "associated data" (AD) which is not made confidential, but its integrity is protected (i.e., it is readable, but tampering with it will be detected). A typical example is the header of a network packet that contains its destination address. To properly route the packet, all intermediate nodes in the message path need to know the destination, but for security reasons they cannot possess the secret key. Schemes that allow associated data provide authenticated encryption wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phillip Rogaway
Phillip Rogaway (also referred to as Phil Rogaway) is an American cryptographer and former professor of computer science at the University of California, Davis. He graduated from Beverly Hills High School, and later earned a BA in computer science from UC Berkeley and completed his PhD in cryptography at MIT, in the Theory of Computation group. He has taught at UC Davis since 1994. He was awarded the Paris Kanellakis Award in 2009 and the first Levchin Prize for Real World Cryptography in 2016. Rogaway received an NSF CAREER award in 1996, which the NSA had attempted to prevent by influencing the NSF. He has been interviewed in multiple media outlets regarding his stance on the ethical obligations that cryptographers and computer scientists have to serve to the public good, specifically in the areas of internet privacy and digital surveillance. Rogaway's papers cover topics including: * CMAC * Concrete security * DES and DES-X * Format-preserving encryption * OCB mode * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adaptive Chosen Ciphertext Attack
An adaptive chosen-ciphertext attack (abbreviated as CCA2) is an interactive form of chosen-ciphertext attack in which an attacker first sends a number of ciphertexts to be decrypted chosen adaptively, and then uses the results to distinguish a target ciphertext without consulting the oracle on the challenge ciphertext. In an adaptive attack, the attacker is further allowed adaptive queries to be asked after the target is revealed (but the target query is disallowed). It is extending the indifferent (non-adaptive) chosen-ciphertext attack (CCA1) where the second stage of adaptive queries is not allowed. Charles Rackoff and Dan Simon defined CCA2 and suggested a system building on the non-adaptive CCA1 definition and system of Moni Naor and Moti Yung (which was the first treatment of chosen ciphertext attack immunity of public key systems). In certain practical settings, the goal of this attack is to gradually reveal information about an encrypted message, or about the decryption k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entropic Security
{{More citations needed, date=September 2022Entropic security is a security definition used in the field of cryptography. Modern encryption schemes are generally required to protect communications even when the attacker has substantial information about the messages being encrypted. For example, even if an attacker knows that an intercepted ciphertext encrypts either the message "Attack" or the message "Retreat", a semantically secure encryption scheme will prevent the attacker from learning which of the two messages is encrypted. However, definitions such as semantic security are too strong to achieve with certain specialized encryption schemes. Entropic security is a weaker definition that can be used in the special case where an attacker has very little information about the messages being encrypted. It is well known that certain types of encryption algorithm cannot satisfy definitions such as semantic security: for example, deterministic encryption algorithms can never be se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NIST AES Key Wrap
The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical science laboratory programs that include nanoscale science and technology, engineering, information technology, neutron research, material measurement, and physical measurement. From 1901 to 1988, the agency was named the National Bureau of Standards. History Background The Articles of Confederation, ratified by the colonies in 1781, provided: The United States in Congress assembled shall also have the sole and exclusive right and power of regulating the alloy and value of coin struck by their own authority, or by that of the respective states—fixing the standards of weights and measures throughout the United States. Article 1, section 8, of the Constitution of the United States, ratified in 1789, granted these powers to the new Cong ... [...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] |
