SLR 9 AND 10 FLASHCARDS

Hashing converts data into a fixed-length unique code called a hash used to verify integrity and enable fast lookup.

Used in password storage (store hashed passwords) and database indexing for quick retrieval.

When two different inputs produce the same hash value.

Encryption where the same key is used to encrypt and decrypt the data.

Encryption that uses a public key to encrypt and a private key to decrypt.

Fast and efficient for encrypting large amounts of data.

Key distribution problem – both parties must securely share the same key.

Secure key exchange without needing to share a secret key beforehand.

Slower than symmetric encryption due to complex mathematical calculations.

A lossless compression method that stores repeated values as one value and a count (e.g. AAAA → A4).

A lossless compression method that replaces repeated strings with shorter references stored in a dictionary.

Compression that removes some data to reduce file size and cannot be perfectly reconstructed.

Compression that preserves all original data so the file can be perfectly reconstructed.

Organised collections of related data stored electronically for efficient retrieval and manipulation.

A real-world object or concept about which data is stored (e.g. Student).

A property or characteristic of an entity (e.g. StudentID, Name).

An attribute that uniquely identifies each record in a table.

An attribute in one table that references the primary key in another table.

Ensures that foreign key values must match a valid primary key value or be null.

A process of structuring a relational database to reduce redundancy and improve integrity.

All attributes contain atomic values and there are no repeating groups.

In 1NF and all non-key attributes fully depend on the entire primary key.

In 2NF and no non-key attribute depends on another non-key attribute.

To reduce redundancy and prevent insertion, deletion and update anomalies.