The term lower-case letter is identified in base64 scheme by the sequence bG93ZXItY2FzZSBsZXR0ZXI=, while the MD5 signature is equal to c20c0c53c351ca00c0992c4a1fd9a06f. The ASCII encoding of lower-case letter in hexadecimal notation is 6c6f7765722d63617365206c6574746572.