Good articles on Schnorr and BLS signature (Better)
Wet Signatures and the Wonderful World of Schnorr …
Signatures are at the core of our world of trust. For centuries we have used them as a legal way of proving our identity and our…
Prof Bill Buchanan OBE
There are a few more related articles on his site.
If you have math background, you might find it important to read articles which get to the point.
There is a good read to BLS signature too. Read it in English by Google Translate.