How safe is contactless payment? || How does RFID & NFC work? || EB#40

How safe is contactless payment? || How does RFID & NFC work? || EB#40

nowadays it is becoming more and more common to use a service like for example Google pay to like the name implies pay for something in a store without using cash even I use a contactless payment methods with my Charu cards which I only have to hold in front of card reader in a

Signing transactions - Blockchain in Javascript (part 4)

Signing transactions – Blockchain in Javascript (part 4)

welcome back to the blockchain in JavaScript series in the previous three videos we have created a simple blockchain in JavaScript we added proof of work and we added transactions and mining rewards but there is a small problem with our current version and that is that anyone can make any transaction that he wants