The term isidor feinstein stone is identified in base64 scheme by the sequence aXNpZG9yIGZlaW5zdGVpbiBzdG9uZQ==, while the MD5 signature is equal to ef2be3725494143e8c4b85e20e78a990. The ASCII encoding of isidor feinstein stone in hexadecimal notation is 697369646f72206665696e737465696e2073746f6e65.