The term concave polyhedron is identified in base64 scheme by the sequence Y29uY2F2ZSBwb2x5aGVkcm9u, while the MD5 signature is equal to b89d8f6e5c068f3d4a8441390cb50196. The ASCII encoding of concave polyhedron in hexadecimal notation is 636f6e6361766520706f6c79686564726f6e.