Is this true, the cryptography which is used in bitcoin allows for leakage of information which could be used to recalculate the private key - IF you are continously reusing the same public address for transactions?
I think there were Faulty client implementations in the past which have and mishandled the protocol and leaked the keys when reusing same address.
If that is correct, is it possible to make any kind of mathematical assumption, how many times of reusing the same address could practically enable the reengineering of the private key?
After how many times of reusage would you strictly advice a user to migrate to another wallet with a new private key? Two times reusage is enough to break the key?