Modern-day hacking and surveillance skills have advanced to such an extent that the hackers do not even need to intercept the actual message while it is travelling through a secured channel. They can guess the information carried by the message by just studying its shadow. By the shadow of a message, we mean the metadata logs and audit trails a message leaves while it is travelling via a channel.

To better understand such attacks, imagine you live in a big city where rents are very high. So, you find an old flat owner downtown who is willing to give you one room for rent, which is within your budget. The only problem is that the rail tracks run too close to your walls. Each night, you can feel the rumbling of your creaky bed when ...

Get Ethereum Smart Contract Development now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.