Cryptography and Block chain development courses

Hello community member,

This will be my very first post here so category might be unsuitable for this kind of post and for that my apologies please.

Now, I have gone through an article which describes that the Cryptography and Block chain development is the trend of 2k18.

I just did my graduation in Computer Science and now i have to specify my domain, which increases my interest to learn Cryptography (bit familiar ), Block chain and smart contract development but my question is Where to start ? is there any book video toturails etc... e.g if i have to learn python there are plenty of courses on plenty of sites which guides from hello world programs to much complex extent and also you can find from their ranking and reviews which one will be good for you.

Thanks