Method of masking application processing of an access request issued to a server by a client workstation connected to this server through successive intermediate proxy servers of the network, conforming to the IP Internet protocol, characterized in that it consists at least in: at the first proxy server reached by the access request message, a) applying an application processing provided by said first intermediate proxy server to said access request; b) entering the IP address of the client workstation in one of the specific data fields of the header of said access request message; and at said successive proxy servers, c) transmitting successively the access request to the next proxy server, using, as the IP source address of the transmitted request, the IP address of the proxy server concerned, and retaining the IP address of the client workstation in the header of said request message, said next proxy server executing an application processing that it provides and, following the successive execution of the application processing and the transmission of said access request by the latter of said successive intermediate proxy servers towards said server; at a masking module interconnected in line to said server, d) intercepting in line said access request; e) removing the address entered in that of said specific fields of the header of said access request message; f) constructing, from the access request message obtained in the preceding step, a masked request message comprising, as the source IP address, the client workstation address and, as the destination IP address, the IP address of said server; g) transmitting from said masking module said masked request message towards said server, which allows said server to process said masked request message, as if the latter came directly from the client workstation. at the first proxy server reached by the access request message, a) applying an application processing provided by said first intermediate proxy server to said access request; b) entering the IP address of the client workstation in one of the specific data fields of the header of said access request message; and a) applying an application processing provided by said first intermediate proxy server to said access request; b) entering the IP address of the client workstation in one of the specific data fields of the header of said access request message; and at said successive proxy servers, c) transmitting successively the access request to the next proxy server, using, as the IP source address of the transmitted request, the IP address of the proxy server concerned, and retaining the IP address of the client workstation in the header of said request message, said next proxy server executing an application processing that it provides and, following the successive execution of the application processing and the transmission of said access request by the latter of said successive intermediate proxy servers towards said server; c) transmitting successively the access request to the next proxy server, using, as the IP source address of the transmitted request, the IP address of the proxy server concerned, and retaining the IP address of the client workstation in the header of said request message, said next proxy server executing an application processing that it provides and, following the successive execution of the application processing and the transmission of said access request by the latter of said successive intermediate proxy servers towards said server; at a masking module interconnected in line to said server, d) intercepting in line said access request; e) removing the address entered in that of said specific fields of the header of said access request message; f) constructing, from the access request message obtained in the preceding step, a masked request message comprising, as the source IP address, the client workstation address and, as the destination IP address, the IP address of said server; g) transmitting from said masking module said masked request message towards said server, which allows said server to process said masked request message, as if the latter came directly from the client workstation. d) intercepting in line said access request; e) removing the address entered in that of said specific fields of the header of said access request message; f) constructing, from the access request message obtained in the preceding step, a masked request message comprising, as the source IP address, the client workstation address and, as the destination IP address, the IP address of said server; g) transmitting from said masking module said masked request message towards said server, which allows said server to process said masked request message, as if the latter came directly from the client workstation.