In cryptography, a block cipher is a deterministic algorithm operating on fixed-length groups of bits, called blocks. They are specified elementary components in the design of many cryptographic protocols and are widely used to encrypt large amounts of data, including in data exchange protocols. It uses blocks as an unvarying transformation.
In computing, Internet Protocol Security (IPsec) is a secure network protocol suite that authenticates and encrypts packets of data to provide secure encrypted communication between two computers over an Internet Protocol network. It is used in virtual private networks (VPNs).
In cryptography, Triple DES, officially the Triple Data Encryption Algorithm, is a symmetric-key block cipher, which applies the DES cipher algorithm three times to each data block. The Data Encryption Standard's (DES) 56-bit key is no longer considered adequate in the face of modern cryptanalytic techniques and supercomputing power. A CVE released in 2016, CVE-2016-2183 disclosed a major security vulnerability in DES and 3DES encryption algorithms. This CVE, combined with the inadequate key size of DES and 3DES, NIST has deprecated DES and 3DES for new applications in 2017, and for all applications by 2023. It has been replaced with the more secure, more robust AES.
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. However, symmetric-key encryption algorithms are usually better for bulk encryption. 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.
In cryptography, a block cipher mode of operation is an algorithm that uses a block cipher to provide information security such as confidentiality or authenticity. A block cipher by itself is only suitable for the secure cryptographic transformation of one fixed-length group of bits called a block. A mode of operation describes how to repeatedly apply a cipher's single-block operation to securely transform amounts of data larger than a block.
CRYPTREC is the Cryptography Research and Evaluation Committees set up by the Japanese Government to evaluate and recommend cryptographic techniques for government and industrial use. It is comparable in many respects to the European Union's NESSIE project and to the Advanced Encryption Standard process run by National Institute of Standards and Technology in the U.S.
One-key MAC (OMAC) is a message authentication code constructed from a block cipher much like the CBC-MAC algorithm.
S/MIME is a standard for public key encryption and signing of MIME data. S/MIME is on an IETF standards track and defined in a number of documents, most importantly RFC 3369, 3370, 3850 and 3851. It was originally developed by RSA Data Security and the original specification used the IETF MIME specification with the de facto industry standard PKCS#7 secure message format. Change control to S/MIME has since been vested in the IETF and the specification is now layered on Cryptographic Message Syntax (CMS), an IETF specification that is identical in most respects with PKCS #7. S/MIME functionality is built into the majority of modern email software and interoperates between them. Since it is built on CMS, MIME can also hold an advanced digital signature.
NSA Suite B Cryptography was a set of cryptographic algorithms promulgated by the National Security Agency as part of its Cryptographic Modernization Program. It was to serve as an interoperable cryptographic base for both unclassified information and most classified information.
Offset codebook mode is an authenticated encryption mode of operation for cryptographic block ciphers. OCB mode was designed by Phillip Rogaway, who credits Mihir Bellare, John Black, and Ted Krovetz with assistance and comments on the designs. It is based on the integrity-aware parallelizeable mode (IAPM) of authenticated encryption by Charanjit S. Jutla. The OCB2 version was proven insecure, while the original OCB1 as well as OCB3 from 2011 are still considered secure.
CCM mode is a mode of operation for cryptographic block ciphers. It is an authenticated encryption algorithm designed to provide both authentication and confidentiality. CCM mode is only defined for block ciphers with a block length of 128 bits.
Authenticated Encryption (AE) and Authenticated Encryption with Associated Data (AEAD) are forms of encryption which simultaneously assure the confidentiality and authenticity of data.
The Secure Real-time Transport Protocol (SRTP) is a profile for Real-time Transport Protocol (RTP) intended to provide encryption, message authentication and integrity, and replay attack protection to the RTP data in both unicast and multicast applications. It was developed by a small team of Internet Protocol and cryptographic experts from Cisco and Ericsson. It was first published by the IETF in March 2004 as RFC 3711.
Disk encryption is a special case of data at rest protection when the storage medium is a sector-addressable device. This article presents cryptographic aspects of the problem. For an overview, see disk encryption. For discussion of different software packages and hardware devices devoted to this problem, see disk encryption software and disk encryption hardware.
EAX mode (encrypt-then-authenticate-then-translate) is a mode of operation for cryptographic block ciphers. It is an Authenticated Encryption with Associated Data (AEAD) algorithm designed to simultaneously provide both authentication and privacy of the message with a two-pass scheme, one pass for achieving privacy and one for authenticity for each block.
In cryptography, Galois/Counter Mode (GCM) is a mode of operation for symmetric-key cryptographic block ciphers which is widely adopted for its performance. GCM throughput rates for state-of-the-art, high-speed communication channels can be achieved with inexpensive hardware resources. The operation is an authenticated encryption algorithm designed to provide both data authenticity (integrity) and confidentiality. GCM is defined for block ciphers with a block size of 128 bits. Galois Message Authentication Code (GMAC) is an authentication-only variant of the GCM which can form an incremental message authentication code. Both GCM and GMAC can accept initialization vectors of arbitrary length.
Cryptography, or cryptology, is the practice and study of techniques for secure communication in the presence of adversarial behavior. More generally, cryptography is about constructing and analyzing protocols that prevent third parties or the public from reading private messages; various aspects of information security such as data confidentiality, data integrity, authentication, and non-repudiation are central to modern cryptography. Modern cryptography exists at the intersection of the disciplines of mathematics, computer science, electrical engineering, communication science, and physics. Applications of cryptography include electronic commerce, chip-based payment cards, digital currencies, computer passwords, and military communications.
In cryptography, format-preserving encryption (FPE), refers to encrypting in such a way that the output is in the same format as the input. The meaning of "format" varies. Typically only finite sets of characters are used; numeric, alphabetic or alphanumeric. For example:
The following outline is provided as an overview of and topical guide to cryptography:
Storage security is a specialty area of security that is concerned with securing data storage systems and ecosystems and the data that resides on these systems.
