What are the characteristics of a quantum secure protocol?

What are the characteristics of quantum secure protocol, and does it always need to be information theoretic to be called as quantum secure? Are the current techniques used in bitcoins quantum secure?

• I'd assume a protocol is quantum-secure if it secure against standard polynomial attackers and attackers with quantum computing abilities.
– SEJPM
Nov 24 '16 at 10:25
• Nov 24 '16 at 11:58

Grover's algorithm might cause some additional issues, including faster mining, $2^{80}$ pre-image attacks against the 160-bit hashes used for bitcoin addresses and faster cracking of weak passphrases for password derived keys.
• @kasperd 1) It's a meet-in-the-middle attack, so the equivalent of grover reduces the cost to $2^{1/3}$ from $2^{1/2}$, so you'd still have 85 bits of security. If you want 128 bits of security, you only need 384 bits of output, not 512. 2) Bernstein argues that the memory access circuitry for that quantum algorithm would bring up the cost beyond the cost of classic collision finders. But I don't know if he overlooked something. Nov 25 '16 at 8:05