A string of leaks had marred the 2018 CBSE boards. Besides the Class XII economics paper, which had to be held again, the Class X maths paper was leaked. Images of solved question papers of some other subjects also went viral. For starters, the system of multiple sets of question papers was reintroduced after two years. This seemed like an easy fix and wouldn’t have stopped leakage during handling.

from Times of India https://timesofindia.indiatimes.com/india/multiple-papers-qr-codes-live-tracking-how-cbse-plugged-paper-leaks-this-year/articleshow/68588388.cms