- "Cryptography, or cryptology, is the practice and study of techniques for secure communication in the presence of adversarial behavior."
It deals with the design of algorithms and protocols for secure communication, including aspects such as confidentiality, integrity, and authenticity.
Encryption: The process of converting plaintext into ciphertext to preserve the confidentiality of the message.
Decryption: The process of converting ciphertext back into plaintext to recover the original message.
Cryptosystems: A set of cryptographic algorithms and protocols used to protect sensitive information.
Symmetric key cryptography: A type of encryption where the same secret key is used for both encryption and decryption.
Asymmetric key cryptography: A type of encryption where a publicly known key is used for encryption and a privately known key is used for decryption.
Hash functions: A mathematical function used to convert data of arbitrary size to a fixed-size output that is used for integrity checking or message authentication.
Digital signatures: An electronic method of verifying the authenticity and integrity of a message or document.
Key exchange protocols: A cryptographic protocol used to exchange keys securely over a public channel.
Steganography: The practice of concealing information within other non-secret text or data to prevent detection.
Cryptanalysis: The study and practice of breaking codes and ciphers to decipher hidden messages.
Symmetric Cryptography: This type of cryptography involves using the same key for both encryption and decryption of the message.
Asymmetric Cryptography: This type of cryptography involves using two different keys for encryption and decryption of the message. This technique is also known as public-key cryptography.
Hybrid Cryptography: This type of cryptography is a combination of both symmetric and asymmetric cryptography, allowing for secure communication between parties.
Block Ciphers: This type of cryptography involves breaking the message up into blocks and then encrypting each block using a key.
Stream Ciphers: This type of cryptography involves encrypting the message one bit at a time, using a key.
Elliptic Curve Cryptography: This form of public-key cryptography is based on the mathematical structure of elliptic curves.
Quantum Cryptography: This type of cryptography uses the principles of quantum mechanics to provide secure communication.
Homomorphic Encryption: This type of cryptography allows for computation to be performed on encrypted data, without the need for decryption.
Zero-Knowledge Proof: This type of cryptography allows a user to prove something without revealing any information about it.
Hash Functions: This type of cryptography is used to generate fixed-length, unique representations of data.
- "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."