This page outlines PEP related actions taken over a series of typical client/server transactions. Data issued by the client is in red and that by the server is blue. Included examples are:
GET /countable/asdf.html HTTP/1.1 Host: pfunk.w3.org Date: Mon, 9 Jun 1997 21:58:39 GMT
client requests resource
HTTP/1.1 420 Bad Extensions Content-Length: 85 PEPInfo: {{id "http://pfunk.w3.org:8887/src/classes/AccessCounter"}{strength must}{for "/countable/" *}} Date: Mon, 9 Jun 1997 21:59:38 GMT Content-Type: text/html <HTML><HEAD><TITLE>Bummer</TITLE></HEAD> <BODY><H1>Bummer</H1>so sorry</BODY></HTML>
GET /countable/asdf.html HTTP/1.1 Host: pfunk.w3.org Date: Mon, 9 Jun 1997 21:58:39 GMT PEP: {{map "http://pfunk.w3.org:8887/src/classes/AccessCounter" AccessCounter-12345}{strength must}} AccessCounter-12345: 1
HTTP/1.1 200 OK Content-Length: 95 PEPInfo: {{id "http://pfunk.w3.org:8887/src/classes/AccessCounter"}{strength must}{for "/countable/" *}} Date: Mon, 9 Jun 1997 21:59:38 GMT Content-Type: text/html AccessCounter-12345: 1 <HTML><HEAD><TITLE>asdf</TITLE></HEAD> <BODY><H1>asdf</H1>All accounted for, sir.</BODY></HTML>
GET /asdf.html HTTP/1.1 Host: pfunk.w3.org Date: Mon, 9 Jun 1997 21:58:39 GMT
client requests resource
HTTP/1.1 200 OK Content-Length: 103 PEPInfo: { {id "http://pfunk.w3.org:8887/src/classes/PostPay"}{strength must}{for "/payola/" *} {id "http://pfunk.w3.org:8887/src/classes/AccessCounter"}{strength may}{for "/" *} {id "http://pfunk.w3.org:8887/src/classes/EscapeBody"}{strength must}{for "/escaped/" *}} Date: Mon, 9 Jun 1997 21:59:38 GMT Content-Type: text/html <HTML><HEAD><TITLE>asdf</TITLE></HEAD> <BODY><H1>asdf</H1>Pretty exciting, huh?</BODY></HTML>
Note: This policy declaration announced AccessCounter as an optional extension that was valid anywhere from the root down. The server could have returned an extension declaration which the client could have ignored if it didn't understand it.
GET /payola/asdf.html HTTP/1.1 Host: pfunk.w3.org Date: Mon, 9 Jun 1997 21:58:39 GMT
client requests resource
HTTP/1.1 200 OK Content-Length: 103 PEP: {{map "http://pfunk.w3.org:8887/src/classes/PostPay" key=K1,price=P1}{strength must}} K1: 118.23.205.22.1df34c8e P1: $.20 Date: Mon, 9 Jun 1997 21:59:38 GMT Content-Type: text/html <HTML><HEAD><TITLE>fdsa</TITLE></HEAD> <BODY><H1>fdsa</H1>?siht rof deyap uoy dalg uoy t'nerA</BODY></HTML>
Note: the server may assume that the majority of commercial clients will
be honest. This allows it to not encrypt the response, saving the client
a round trip with the key server. This would work until someone hacks up
a proxy server to strip out the PEP header and allow even honest clients
to cheat on payment.