1. They showed how to use secure cryptography to implement a blackmail attack with key public information .
2. They showed how to use secure cryptography to implement a public key information extortion attack .

yes

1. The Calova River is a tributary of the Temesch River in Romania .
2. The Timis River is a tributary of the River Calova in Romania .

no

1. However , the original flag had a brownish colour instead of green .
2. The original flag , however , had a green color instead of brownish .
no