What's 2*80 in Hexa? (AES key expansion Round Key confusion)

[blueberry123]

What's 2*80 in Hexa?

EDIT: shady looking link

The result is shown to be 1B. How did we get this value?

So, this looks like a case of carry in hexa addition, so how'd we do this calculation?


I'm asking this question because of this. Here' for j=8, Round Constant is 80. The formula to find next round constant is to multiply the current round constant with 2. So, it's 2*80 and should be 100. But it's not the case. So, I want to know how is it done?

Source: EDIT: shady looking link

[deanwebb]

Edited the links, they did not look like good places to go. If they are legit, please just post the search terms that will point to them. Or an image.

[deanwebb]

1B hex is 27 dec so that makes as no sense.