noun | uh·tak sur·fis
All the places where some l33t haxx0r could pwn your system and steal your private keys (and your dignity). The more complex your code, the bigger your attack surface. It's like leaving your front door, back door, and all your windows wide open and then being surprised when you get robbed.
Example
"We need to audit our smart contract for vulnerabilities. I don't want to end up like Mt. Gox!"
"The new update to the Bitcoin protocol reduced the attack surface by 69%. Nice."
