How is same signed transaction not reusable, also quantum security of ECDSA? - page 2.

Please excuse my raw ignorance, could someone be so kind as to explain to me how Bitcoin prevents a same signed transaction from being reused in a subsequent block to send the same amounts from the same inputs to the same outputs again? Is there a Nonce hashed in the signature and the Nonce is also retrievable?

Tangentially I understand a Nonce is part of the ECDSA algorithm and that can be problematic if the RNG is defective:

http://blog.cryptographyengineering.com/2012/03/surviving-bad-rng.html
http://bitcoin.stackexchange.com/questions/12879/would-a-transition-to-a-different-signature-scheme-be-feasible
http://en.wikipedia.org/wiki/Elliptic_Curve_DSA#Security

My second question is there any signature algorithm that is both quantum secure and can have unlimited use (data size of the signature is not a concern in my case, yet data size of the public key needs to be compact):

http://bitcoinmagazine.com/6021/bitcoin-is-not-quantum-safe-and-how-we-can-fix/

Third question is doesn't the above obviate one of the reasons given for allowing multiple transaction outputs (i.e. sending change to yourself), and leave only remaining dubious justification?

http://bitcoin.stackexchange.com/questions/1629/why-does-bitcoin-send-the-change-to-a-different-address#comment2088_1637

Topic: How is same signed transaction not reusable, also quantum security of ECDSA? - page 2. (Read 6574 times)