Let say I got a library to read/write files securely on the hard disk (encrypt before writing and decrypt to read back). If the library is severely obfuscated, attackers may be intimidated. So they may not be able to reverse to find the crypto key in the library. However they can use the library as a whole to decrypt previously encrypted files.
So as said in the title, what is the terminology used to describe the attacks of extracting an application's shared library and using it stand-alone?