Multiple choice single answer exercise 3

Free PTE reading practice 9 Multi choice single answerFor this free PTE reading practice, we will look at multiple questions which have single answers. For this question type, you are given a text up to 300 words long, and will need to select the correct answer. You only need to select one answer.

Here’s a practice exercise to test your skills this with PTE question type.


The 20th century, and latterly the computer age, has seen remarkable advances in the art of cryptography (the creation of codes). Both World Wars necessitated innovative approaches to coded communication. World War I saw electromechanical devices employ a new concept, called the ‘one-time pad’, a change whereby the key was now used only once. Interestingly, during America’s Prohibition years, criminals used the latest cryptography methods to keep their communications private. One of the greatest of all encryption devices was the German Enigma machine used during World War II. Years of early work by Polish mathematicians and later by British code-breakers eventually allowed Allied command to decipher the messaging, which proved important in the outcome of the war.

After the Second World War, and with the emergence of globalisation and a competitive commercial environment, businesses also began looking at encryption, which hitherto had been used almost exclusively for military purposes, as a way to protect sensitive commercial information. IBM, the then-computer giant, pioneered encryption systems to be used commercially and their designs were adopted by the U.S. government as a standard. Once the Internet became an integral part of doing business in the 1990s, the need for encryption moved up a gear because of the availability of so much information and transactional Internet business. Ironically, computers helped with creating ever more complex encryption keys, such as the asymmetric key cypher using two mathematical algorithms, but at the same time, they also saw the birth of ‘brute-force’ computer attacks in an attempt to break codes.