Passwords, Cryptography, Threat modelling Flashcards
What is a hash function?
A one-way function that is relatively easy to compute but hard to reverse.
What is the purpose of salt in password hashing?
A randomly generated string combined with the entered password to create a unique hashed password. The salt and the password is stored somewhere to be able to verify when a user tries to log in. This ensures that if two people have the same password, they will still have different hash values.
What is a Rainbow Table Attack?
A method used by hackers to exploit hashed passwords when two users have the same hash. If two people have the same hash, and the hackers knows the password from one person that has that hash, then the hackers will be able to get access to everyone with that hash. This can be stopped by using salt.
Name three strategies for improving password security.
- Rule enforcement
- List of passwords that aren’t allowed
- Display number of failed logins
- Password ageing
- Prevent users from reverting to old passwords
- Limit login attempts
What are the main password cracking strategies?
- Exhaustive search (brute force)
- Intelligent search (dictionary attacks) - Try passwords associated with the user such as names, pets, etc.
What are the four complementary courses of action in security implementation?
- Prevention
- Detection
- Response
- Recovery
What is cryptography?
A technique for securing data through encoding methods, preventing unauthorized access, modification, or theft.
What is plaintext?
The original message or data fed into the algorithm as input.
What is a secret key in symmetric cryptography?
The piece of information used to encrypt and decrypt messages.
What is ciphertext?
The scrambled message produced as output from the encryption process. It depends on the plaintext and the encryption key. Different key produces different ciphertext for a message.
What does the decryption algorithm do?
It reverses the encryption algorithm to produce the original plaintext.
List the key goals of cryptography.
- Confidentiality - Ensuring that data is only accessible to authorized users.
- Integrity - Ensuring data is not altered during transmission or storage.
- Authentication - Verifying the identity of the sender or receiver.
- Non-Repudiation - Preventing denial of actions (e.g., proof of a transaction)
What is symmetric encryption?
A type of encryption that uses a single key for both encryption and decryption.
What is asymmetric encryption?
A type of encryption that uses two keys: a public key for encryption and a private key for decryption.
Fill in the blank: Hashing is a type of _______ cryptography.
one-way
What is a digital signature?
A mechanism that ensures authenticity and non-repudiation of messages using asymmetric encryption.
What is a digital certificate?
An electronic document used to prove the ownership of a public key, issued by a Certificate Authority.
A certificate is a message signed by an issuer, containing the subject’s name and public key.
A digital certificate is an electronic document used to prove the ownership of a public key. It is issued by a trusted third party known as a Certificate Authority (CA). Digital certificates are widely used in secure communications, such as HTTPS for websites, email encryption, and digital signatures.
Name a cryptographic protocol used for secure web browsing.
- SSL/TLS: Secure web browsing (HTTPS).
- PGP (Pretty Good Privacy): Encrypting emails.
- Blockchain Cryptography: Used in cryptocurrencies like Bitcoin.
What differentiates stream ciphers from block ciphers?
Stream ciphers encrypt data continuously, while block ciphers encrypt fixed-size blocks of data.
Stream ciphers are suitable for scenarios requiring fast, continuous data encryption, while block ciphers are better for securely handling larger datasets. Both types play crucial roles in modern cryptography, and the choice between them depends on the specific requirements of the application.
What does the term ‘attack surface’ refer to?
The total number of possible points where an attacker can try to exploit a system.
What is an attack tree?
An attack tree is a branching, hierarchical data structure that represents a set of potential techniques for exploiting security vulnerabilities.
The root node of the tree is the goal of the attack;
The ways that an attacker could reach that goal are iteratively and incrementally represented as branches and sub-nodes of the tree;
Each sub-node defines a subgoal, and each subgoal may have its own set of further subgoals, etc.
What are adversarial input attacks in machine learning?
Attacks that modify characteristics of observations to fool the model into incorrect classifications.
What are data poisoning attacks?
Attacks that inject bad data into the training data pool, causing the model to learn incorrect patterns.
