Namespace session storage more explicitly.

lib/store/session.js

@@ -4,7 +4,7 @@ var randtoken = require('rand-token');
 
 function SessionStore(options) {
   options = options || {};
-  this._key = options.key || 'ethereum';
+  this._key = options.key || 'ethereum:siwe';
 }
 
 SessionStore.prototype.challenge = function(req, cb) {

test/strategy.test.js

@@ -34,7 +34,7 @@ describe('Strategy', function() {
         };
         req.session = {
           messages: [],
-          ethereum: {
+          'ethereum:siwe': {
             nonce: 'VjglqeaSMDbPSYe0K'
           }
         };