An infusion pump having improved network access security, comprising: a memory configured to store infusion pump data; a pump configured to pump a medicament from a source to a human patient; a network interface circuit configured to provide communications over a network; and a processing circuit configured to control the pump and to: retrieve infusion pump data from the infusion pump memory for transmission to a remote server computer; hash the infusion pump data using a first cryptographic function to provide a first hashed code, generate header data for a header portion of a Hypertext Transfer Protocol request message, generate a time stamp; hash the header data, time stamp and first hashed code using a second cryptographic hash function and a cryptographic key to provide a second hashed code for the header portion, wherein the first cryptographic function is the same as or different than the second cryptographic hash function, wherein the cryptographic key is a shared cryptographic key which is shared between the infusion pump and the remote server computer out of band; insert the second hashed code into the header portion of the Hypertext Transfer Protocol request message; insert the infusion pump data into a body portion of the Hypertext Transfer Protocol request message; generate a request line for the Hypertext Transfer Protocol request message; and transmit the Hypertext Transfer Protocol request message to the remote server computer over the communications network. a memory configured to store infusion pump data; a pump configured to pump a medicament from a source to a human patient; a network interface circuit configured to provide communications over a network; and a processing circuit configured to control the pump and to: retrieve infusion pump data from the infusion pump memory for transmission to a remote server computer; hash the infusion pump data using a first cryptographic function to provide a first hashed code, generate header data for a header portion of a Hypertext Transfer Protocol request message, generate a time stamp; hash the header data, time stamp and first hashed code using a second cryptographic hash function and a cryptographic key to provide a second hashed code for the header portion, wherein the first cryptographic function is the same as or different than the second cryptographic hash function, wherein the cryptographic key is a shared cryptographic key which is shared between the infusion pump and the remote server computer out of band; insert the second hashed code into the header portion of the Hypertext Transfer Protocol request message; insert the infusion pump data into a body portion of the Hypertext Transfer Protocol request message; generate a request line for the Hypertext Transfer Protocol request message; and transmit the Hypertext Transfer Protocol request message to the remote server computer over the communications network. retrieve infusion pump data from the infusion pump memory for transmission to a remote server computer; hash the infusion pump data using a first cryptographic function to provide a first hashed code, generate header data for a header portion of a Hypertext Transfer Protocol request message, generate a time stamp; hash the header data, time stamp and first hashed code using a second cryptographic hash function and a cryptographic key to provide a second hashed code for the header portion, wherein the first cryptographic function is the same as or different than the second cryptographic hash function, wherein the cryptographic key is a shared cryptographic key which is shared between the infusion pump and the remote server computer out of band; insert the second hashed code into the header portion of the Hypertext Transfer Protocol request message; insert the infusion pump data into a body portion of the Hypertext Transfer Protocol request message; generate a request line for the Hypertext Transfer Protocol request message; and transmit the Hypertext Transfer Protocol request message to the remote server computer over the communications network.