1 What precisely is the meaning of "reusing"? Is it receiving multiple times coins to the same btc address? Or is it also about sending coins?
2 How can people avoid this leaking of information when using a wallet, best practices?
3 How many times of reusing could be enough to seriously allow leakage/reingeneering of the key? Just one time is enough ? Possible to make any estimations?
4 Is this reusing problem only inherent to bitcoin? Or which other blockchains would you know of with same issues?