Security Dictionary
Defence in Depth - When one measure breaks, there will be multiple more measures of protection.
Single Point of Failure - When one defensive measure breaks, the system is vulnerable.
Security By Design - Before implementing a system, security features are planned ahead of time to prevent attacks.
Apes vs Ants - Ants rely on complete obedience for the colony to thrive. Apes have agency and freedom, and this individualism can work against the society’s goals. Thus, we need to ensure people’s individualism oppose each other to strike a balance. For example, police who receive renumeration and recognition, against criminals who have the chance at wealth.
Bell-LaPadula model - Enforcing access controls into different security levels.
Side Channels - Every action in the virtual world leaves a physical trace. For example, increased graphics card usage for crypto mining will draw more power.
Attack on Journos - Targeting the source of information by attacking journalists.
Vigenere Cipher - Method of encrypting alphabetic text by using a series of interwoven Caesar ciphers based on letters of a keyword.
Kasiski Examination - Method of attacking the Vienere Cipher where it allows the cryptanalyst to deduce the length of the keyword. Afterwards, the cryptanalyst lines up the ciphertext in n columns, and each column will be treated as a monoalphabetic substitution cipher that can be attacked using regular frequency analysis.
Engima Machine - An encryption device that converts plain text to ciphertext and vice versa. Relied on rotors, keyboards, etc and was used extensively by Naxi Germany during WWII.
One Time Pad - Encryption technique that cannot be cracked, but requires the use of a one-time pre-shared key the same length as the message being sent. Essentially, a Vigenere Cipher with the password length equal to the message size.
Type 1 Error - False positive. An outcome is percieved as correct, however the outcome is in fact false.
Type 2 Error - False negative. An outcome is perceived as incorrect. However the outcome is in fact true.
The index of coincidence - a measure of how similar a frequency distribution is to the uniform distribution.
Reflection:
This week’s lecture was like opening a can of worms. Each worm being a new and interesting security concept. I particularly liked the analogies used like castles in defence in depth.