2.8 Flashcards
Summarize the basics of cryptographic concepts.
Is a cryptographic implementation designed to demonstrate authenticity and identity associated with a message.
Digital signatures
As a general rule, a longer key length is more secure, but also will take longer to compute.
Key length
Is a mechanism that takes what would be weak keys and “stretches” them to make the system more secure against brute force attacks.
Key stretching
The level of randomness.
Entropy
Refers to the process of adding random data to plaintext before it is hashed. This technique is commonly used in password hashing to enhance security and mitigate various attacks.
Salting
Is a special mathematical function that performs one-way encryption, which means that once the algorithm is processed, there is no feasible way to use the ciphertext to retrieve the plaintext that was used to generate it.
Hashing function
Is a fundamental concept in cryptography that involves securely establishing a shared secret key between two parties over an insecure communication channel. This shared key can then be used to encrypt and decrypt messages exchanged between the parties, ensuring confidentiality and integrity of communication.
Key exchange
Is a branch of public key cryptography that relies on the algebraic structure of elliptic curves over finite fields to provide security functions. It is widely used for secure communication, digital signatures, and encryption.
Elliptic-curve cryptography (ECC)
Is a property of a public key system in which a key derived from another key is not compromised, even if the originating key is compromised in the future.
Perfect forward secrecy (PFS)
Is the use of quantum computing hardware to perform encryption and decryption processes.
Quantum Cryptography
Are cryptographic keys that are used only once after generation.
Ephemeral keys
In symmetric or block encryption, there is a need to deal with multiple blocks of identical data to prevent multiple blocks of ciphertext that would identify the blocks of identical input data. There are multiple methods of dealing with this. The basic premise is to use some source of entropy before encrypting subsequent blocks so that identical blocks of plaintext produce differing blocks of ciphertext. These modes can be broken into three groups: authenticated, unauthenticated, and counter.
Modes of operation
Is a form of encryption designed to provide both confidentiality and authenticity services.
Authenticated
is a cryptographic process where data is encrypted to ensure its confidentiality but lacks mechanisms for verifying the integrity or authenticity of the encrypted data.
Unauthenticated
Is a block cipher mode of operation used in symmetric encryption algorithms to provide confidentiality for data. It transforms a block cipher into a stream cipher, allowing encryption of plaintext data of arbitrary length. Is widely used in various cryptographic applications due to its simplicity, efficiency, and parallelizability.
Counter
Are lists of records, where each addition to the list is done by a cryptographic algorithm.
Blockchains
Are distributed and decentralized databases that store a continuously growing list of records, called blocks, which are linked and secured using cryptographic techniques. These ledgers are publicly accessible and transparent, allowing anyone to view, verify, and audit the transactions recorded on the blockchain.
Public ledgers
A set of algorithms used together in cryptography.
Cipher suites
Operate on streams of data instead of blocks. A _________ cipher encrypts plaintext one byte at a time.
Stream ciphers
Operate on input data in a series of blocks. A _____________ cipher encrypts plaintext one block at a time.
Block ciphers
__________________ tends to be faster, is less computationally involved, and is better for bulk transfers. But it suffers from a key management problem in that keys must be protected from authorized parties. Uses one key, and it is faster but less secure.
Symmetric encryption
__________________ resolve the key secrecy issue with public keys, but they add significant computational complexity, which makes them less suited for bulk encryption. Uses two keys, and it is slower but more secure.
Asymmetric encryption
Is a specialized suite of cryptographic algorithms designed to operate in a resource-constrained environment.
Lightweight cryptography
Is the practice of concealing secret information within non-secret data in such a way that the existence of the hidden information is not apparent to observers.
Steganography
Is a set of algorithms that allows operations to be conducted on encrypted data, without decrypting and re-encrypting.
Homomorphic encryption
