OCR A Level Unit 1.3

What is Asymmetric Encryption?

• An encryption technique where the same key is used to encrypt and decrypt data.

• A type of lossless compression where text is searched for entries that match the entries in a dictionary.

• An encryption technique where a public key is used to encrypt data and a private key is used to decrypt it.

• A one-way transformation of data into an abbreviated form called a hash value.

Which of the following is a type of lossless compression?

• Lossy Compression

• Hashing

• Symmetric Encryption

• Dictionary Coding

What is the purpose of Hashing?

• To encrypt data using a public key.

• To transform data into an abbreviated form called a hash value.

• To compress data by removing non-essential information.

• To describe the data tables and relationships between them visually.

Which compression algorithm retains all the data in the file by storing the instructions needed to reconstruct the original file?

• Lossy Compression

• Lossless Compression

• Ren-Length Encoding

• Dictionary Coding

What is the main characteristic of Lossy Compression?

• It retains all the data in the file.

• It removes non-essential data from a file, leading to a noticeable decrease in accuracy.

• It uses a public key to encrypt data.

• It transforms data into a hash value.

What does Ren-Length Encoding do?

• It uses a public key to encrypt data.

• It transforms data into a hash value.

• It stores repeated occurrences of the same data as single data values with their counts.

• It removes non-essential data from a file.

What is Symmetric Encryption?

• An encryption technique where a public key is used to encrypt data and a private key is used to decrypt it.

• A type of lossless compression where text is searched for entries that match the entries in a dictionary.

• An encryption technique where the same key is used to encrypt and decrypt data.

• A one-way transformation of data into an abbreviated form called a hash value.

What is the definition of First Normal Form (1NF)?

• A table with no repeating attributes.

• A table with repeating attributes.

• A table with multiple primary keys.

• A table with no primary keys.

What is a Foreign Key?

• A linking attribute that joins two tables in a relational database.

• A unique identifier for each record in a table.

• A key that can be used as an alternative index.

• A key that prevents simultaneous access to data.

What does Isolation in database transactions ensure?

• No transaction should overwrite other transactions that are simultaneously occurring.

• The process of creating an index of primary keys.

• The unnecessary repetition of a field in multiple tables.

• The idea of keeping a database consistent.