A method begins by a dispersed storage (DS) processing module generating a certificate signing request (CSR) that includes a certificate and a certificate extension, wherein the certificate includes information regarding a requesting device and wherein the certificate extension includes information regarding an accessible dispersed storage network (DSN) address range for the requesting device. The method continues with the DS processing module outputting the CSR to a certificate authority of a DSN and receiving a signed certificate from the certificate authority, wherein the signed certificate includes a certification signature of the certificate authority authenticating the certificate and the certificate extension. The method continues with the DS processing module storing the signed certificate for use when generating a DSN access request, wherein the DSN access request is requesting access to dispersed storage error encoded data in the DSN at an address within the accessible DSN address range.