- "Cryptography, or cryptology, is the practice and study of techniques for secure communication in the presence of adversarial behavior."
Provides an overview of cryptography concepts, including encryption, decryption, digital signatures, hashing, and public key infrastructure (PKI).
Symmetric Key Cryptography: The encryption and decryption of data using a shared key.
Asymmetric Key Cryptography: The encryption and decryption of data using a public key and a private key.
Hash Functions: A mathematical function that takes input data and produces a fixed-size output that is unique to the input.
Digital Signatures: A digital signature is a technique that is used to validate the authenticity and integrity of a message, software or digital document.
Key Exchange Algorithms: A protocol that enables two parties to establish a shared secret key securely.
Block Ciphers: A block cipher is a type of symmetric key encryption that works on fixed-length blocks of data.
Stream Ciphers: A stream cipher is a type of symmetric key encryption that works on a continuous stream of data.
Public Key Infrastructure (PKI): A complete system of cryptographic methods, protocols and procedures for managing digital certificate and public key encryption.
Encryption Standards: Standards and protocols for encryption algorithms and key exchange protocols, such as AES, RSA, and Diffie-Hellman.
Cryptographic protocols: Secure communication protocols such as SSL/TLS, IPSec, SSH which are based on a combination of different cryptographic primitives.
PKCS and X.509: Public key cryptography standards and specifications for digital certificates used in PKI.
Cipher Modes: The different modes of operation for block ciphers, such as ECB, CBC, CFB, and OFB.
Hash Algorithms: Different types and standards of hash algorithms like SHA-1, SHA-2, and SHA-3.
Quantum Cryptography: A field of study that deals with the application of principles of quantum mechanics in cryptography.
Cryptanalysis: Methods for breaking cryptographic systems or keys.
Side-Channel Attacks: Cryptography attacks launched by exploiting the security weaknesses of the hardware devices running cryptography.
Digital Certificates: A mechanism to associate a cryptographic key with an identity or name. It is issued and signed by a trusted third-party certificate authority.
Authentication: Techniques to verify the identity of communication partners.
Non-repudiation: A state of being able to prove that a message was indeed sent by the claimed sender and it cannot be refuted later.
Key Management: A set of processes and procedures for generating, storing, and distributing cryptographic keys.
Symmetric Key Cryptography: This involves the use of the same key to encrypt and decrypt data.
Asymmetric Key Cryptography: Also known as Public Key Cryptography, it uses a pair of different keys: One public and one private - to encrypt and decrypt data respectively.
Hash Functions: A one-way function that transforms data into a fixed-length output, which is difficult to reverse and is primarily used to ensure integrity of data.
Message Authentication Codes: It is a combination of a secret key and a hash function that ensures both integrity and authenticity of a message.
Digital Signatures: It involves the use of public key cryptography and hash functions to provide non-repudiation and authenticity for electronic documents and transactions.
Key Management: It is the process of generating, distributing, storing, and revoking keys used in various cryptographic algorithms.
Random Number Generation: Cryptographic systems require genuinely unpredictable random numbers, and this principle describes the methods to generate such numbers.
Key Exchange: It involves the secure exchange of keys between two or more parties to establish a secure session or communication channel.
Diffie-Hellman Algorithm: A specific key exchange algorithm used to enable secure communication between two parties without a shared secret.
Elliptic Curve Cryptography: A type of public key cryptography that uses elliptic curves over finite fields to establish secure communication between parties.
Quantum Cryptography: It uses the principles of quantum mechanics to enable secure communication by exploiting the properties of photons.
Zero-Knowledge Proofs: A method of demonstrating a valid claim without revealing any additional information other than the truth of the statement.
Steganography: Concealing messages or data within other files or media to ensure confidentiality and privacy.
Homomorphic Encryption: A type of encryption that allows computations to be performed on encrypted data without decrypting it, thereby preserving confidentiality.
- "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 (data confidentiality, data integrity, authentication, and non-repudiation) are also central to cryptography."
- "Practical applications of cryptography include electronic commerce, chip-based payment cards, digital currencies, computer passwords, and military communications."
- "Cryptography prior to the modern age was effectively synonymous with encryption, converting readable information (plaintext) to unintelligible nonsense text (ciphertext), which can only be read by reversing the process (decryption)."
- "The sender of an encrypted (coded) message shares the decryption (decoding) technique only with the intended recipients to preclude access from adversaries."
- "The cryptography literature often uses the names 'Alice' (or 'A') for the sender, 'Bob' (or 'B') for the intended recipient, and 'Eve' (or 'E') for the eavesdropping adversary."
- "Since the development of rotor cipher machines in World War I and the advent of computers in World War II, cryptography methods have become increasingly complex and their applications more varied."
- "Modern cryptography is heavily based on mathematical theory and computer science practice; cryptographic algorithms are designed around computational hardness assumptions."
- "Such schemes, if well designed, are therefore termed 'computationally secure'."
- "Theoretical advances (e.g., improvements in integer factorization algorithms) and faster computing technology require these designs to be continually reevaluated and, if necessary, adapted."
- "While it is theoretically possible to break into a well-designed system, it is infeasible in actual practice to do so."
- "Information-theoretically secure schemes that provably cannot be broken even with unlimited computing power, such as the one-time pad, are much more difficult to use in practice than the best theoretically breakable but computationally secure schemes."
- "The growth of cryptographic technology has raised a number of legal issues in the Information Age."
- "Cryptography's potential for use as a tool for espionage and sedition has led many governments to classify it as a weapon and to limit or even prohibit its use and export."
- "In some jurisdictions where the use of cryptography is legal, laws permit investigators to compel the disclosure of encryption keys for documents relevant to an investigation."
- "Cryptography also plays a major role in digital rights management and copyright infringement disputes with regard to digital media."