Obfuscating Point Functions With Multibit Output

The authors construct obfuscators of point functions with multibit output and other related functions. A point function with multibit output returns a fixed string on a single input point and zero everywhere else. Obfuscation of such functions has a useful application as a strong form of symmetric encryption which guarantees security even when the key has very low entropy: essentially, learning information about the plaintext is paramount to finding the key via exhaustive search on the key space.