The term index of refraction is identified in base64 scheme by the sequence aW5kZXggb2YgcmVmcmFjdGlvbg==, while the MD5 signature is equal to 4e486625b9dc3bcc024b2e23813cd6aa. The ASCII encoding of index of refraction in hexadecimal notation is 696e646578206f662072656672616374696f6e.