diff --git a/checkin_notes b/checkin_notes
index e87a429251..39e19993f6 100755
--- a/checkin_notes
+++ b/checkin_notes
@@ -24139,3 +24139,9 @@ David  6 Feb 2005
     sched/
         sched_locality.C
         sched_send.C,h
+
+David  7 Feb 2005
+    - add "web service" for verifying a user CPID and an authenticator
+
+    html/user/
+        verify_cpid.php
diff --git a/html/user/verify_cpid.php b/html/user/verify_cpid.php
new file mode 100644
index 0000000000..fd7cbfc769
--- /dev/null
+++ b/html/user/verify_cpid.php
@@ -0,0 +1,31 @@
+<?php
+
+// "web service" for verifying that a user CPID matches an account key
+
+require_once("../inc/db.inc");
+
+db_init();
+
+$cpid = process_user_text($_GET["cpid"]);;
+$authenticator = process_user_text($_GET["authenticator"]);;
+
+if (!$cpid || !$authenticator) {
+    echo "<error>missing argument</error>\n";
+    exit();
+}
+
+$user = lookup_user_auth($authenticator);
+
+if (!$user) {
+    echo "<error>bad authenticator</error>\n";
+    exit();
+}
+
+$x = $user->cross_project_id.$user->email_addr;
+if (md5($x) == $cpid) {
+    echo "<success></success>\n";
+} else {
+    echo "<error>bad CPID</error>\n";
+}
+
+?>