A-Level IT - Advanced Analysis & Emerging Tech (Hard)

Front

Compare Symmetric and Asymmetric encryption regarding key management and speed.

Back

Symmetric encryption uses one shared key for encryption and decryption. It is computationally fast and efficient for large data streams but poses a secure key distribution challenge. Asymmetric encryption uses a public/private key pair, solving the distribution issue (key exchange), but is significantly slower, making it suitable only for small data like keys or digital signatures.

Front

Define Third Normal Form (3NF) and its specific requirements.

Back

A table is in 3NF if it is already in 2NF AND contains no transitive dependencies. This means no non-prime attribute should depend on another non-prime attribute. All non-prime attributes must depend directly on the primary key, ensuring data isn't duplicated through logical associations.

Front

Calculate the File Size of a 10-minute, 48kHz, 16-bit Stereo audio file.

Back

Formula: Sample Rate × Bit Depth × Channels × Time. Calculation: 48,000 Hz × 16 bits × 2 channels × 600 seconds = 921,600,000 bits; ÷ 8 = 115,200,000 bytes; ÷ 1,000,000 = 115.2 MB.

Front

Explain the role of the 'Handshake' in the TCP protocol stack.

Back

TCP uses a 'Three-Way Handshake' (SYN, SYN-ACK, ACK) to establish a reliable connection between sender and receiver before data transmission. This process synchronizes sequence numbers and acknowledges the readiness of both devices, ensuring the connection is active and stable to prevent data loss during the session.

Front

Distinguish between Verification and Validation in software testing.

Back

Verification answers 'Are we building the product right?'—checking that the software conforms to the technical specifications and requirements documentation without running the code (static testing). Validation answers 'Are we building the right product?'—checking that the final software meets the actual needs of the user and business context (dynamic testing).