diff --git a/config/default.yml b/config/default.yml
index a1b7a5352..3964a7ec5 100644
--- a/config/default.yml
+++ b/config/default.yml
@@ -58,7 +58,9 @@ gatekeeper:
     - header
     - getParam
     - basicAuthUsername
-  api_key_cache: true
+  api_key_cache: false
+  pep_host: 127.0.0.1 # ip or hostname of Pep Proxy host
+  pep_port: 8090 # listen port of Pep Proxy
 trafficserver:
   host: 127.0.0.1
   port: 14009
@@ -282,12 +284,12 @@ apiSettings:
       message: The requested URL was not found on this server.
     api_key_missing:
       status_code: 403
-      code: API_KEY_MISSING
-      message: No api_key was supplied. Get one at {{signup_url}}
+      code: API_KEY_OR_TOKEN_MISSING
+      message: No api_key or token was supplied. Get one at {{signup_url}}
     api_key_invalid:
       status_code: 403
-      code: API_KEY_INVALID
-      message: An invalid api_key was supplied. Get one at {{signup_url}}
+      code: API_KEY_OR_TOKEN_INVALID
+      message: An invalid api_key or token was supplied. Get one at {{signup_url}}
     api_key_disabled:
       status_code: 403
       code: API_KEY_DISABLED
@@ -298,8 +300,8 @@ apiSettings:
       message: The api_key supplied has not been verified yet. Please check your e-mail to verify the API key. Contact us at {{contact_url}} for assistance
     api_key_unauthorized:
       status_code: 403
-      code: API_KEY_UNAUTHORIZED
-      message: The api_key supplied is not authorized to access the given service. Contact us at {{contact_url}} for assistance
+      code: API_KEY_OR_TOKEN_UNAUTHORIZED
+      message: The api_key or token supplied is not authorized to access the given service. Contact us at {{contact_url}} for assistance
     over_rate_limit:
       status_code: 429
       code: OVER_RATE_LIMIT
@@ -368,4 +370,4 @@ ban:
     message: "Please contact us for assistance."
 ember_server:
   port: 14050
-  live_reload_port: 14051
+live_reload_port: 14051
\ No newline at end of file
diff --git a/src/api-umbrella/proxy/hooks/rewrite.lua b/src/api-umbrella/proxy/hooks/rewrite.lua
index af0a2268f..d238ea134 100644
--- a/src/api-umbrella/proxy/hooks/rewrite.lua
+++ b/src/api-umbrella/proxy/hooks/rewrite.lua
@@ -17,6 +17,7 @@ wait_for_setup()
 -- ngx.var lookups are apparently somewhat expensive.
 ngx.ctx.args = ngx_var.args
 ngx.ctx.arg_api_key = ngx_var.arg_api_key
+ngx.ctx.arg_token = ngx_var.arg_token
 if(config["router"]["match_x_forwarded_host"]) then
   ngx.ctx.host = ngx_var.http_x_forwarded_host or ngx_var.http_host or ngx_var.host
 else
@@ -24,6 +25,7 @@ else
 end
 ngx.ctx.host_normalized = host_normalize(ngx.ctx.host)
 ngx.ctx.http_x_api_key = ngx_var.http_x_api_key
+ngx.ctx.http_x_auth_token = ngx_var.http_x_auth_token
 ngx.ctx.port = ngx_var.real_port
 ngx.ctx.protocol = ngx_var.real_scheme
 ngx.ctx.remote_addr = ngx_var.remote_addr
@@ -69,4 +71,4 @@ else
   else
     error_handler(api_err)
   end
-end
+end
\ No newline at end of file
diff --git a/src/api-umbrella/proxy/middleware/api_key_validator.lua b/src/api-umbrella/proxy/middleware/api_key_validator.lua
index ab1447b32..5c6e691b1 100644
--- a/src/api-umbrella/proxy/middleware/api_key_validator.lua
+++ b/src/api-umbrella/proxy/middleware/api_key_validator.lua
@@ -6,32 +6,47 @@ local is_empty = types.is_empty
 
 local function resolve_api_key()
   local api_key_methods = config["gatekeeper"]["api_key_methods"]
-  local api_key
+  local key = {key_value="", key_type="" }
 
+  -- The api_key variable is a dictionary compose by two elements, the key_value which stores
+  -- the api_key value or the user token value and the key_type field in where is stored
+  -- the type of key that was provided by the user, it value could be an api_key or a token.
+  -- The validation process is made for all the api_key_methods (except basicAuthUsername)
+  -- declared in the configuration file checking if the user sends an api_key or token
+  -- Only the header and get_param methods are supported by the token validation.
   for _, method in ipairs(api_key_methods) do
-    if method == "header" then
-      api_key = ngx.ctx.http_x_api_key
-    elseif method == "getParam" then
-      api_key = ngx.ctx.arg_api_key
-    elseif method == "basicAuthUsername" then
-      api_key = ngx.ctx.remote_user
+    if method == "header" and ngx.ctx.http_x_api_key then
+      key.key_value = ngx.ctx.http_x_api_key
+      key.key_type = "api_key"
+    elseif ngx.ctx.http_x_auth_token then
+      key.key_value = ngx.ctx.http_x_auth_token
+      key.key_type = "token"
+    elseif method == "getParam" and ngx.ctx.arg_api_key then
+      key.key_value = ngx.ctx.arg_api_key
+      key.key_type = "api_key"
+    elseif ngx.ctx.arg_token then
+      key.key_value = ngx.ctx.arg_token
+      key.key_type = "token"
+    elseif method == "basicAuthUsername" and ngx.ctx.remote_user then
+      key.key_value = ngx.ctx.remote_user
+      key.key_type = "api_key"
     end
 
-    if not is_empty(api_key) then
+    if not is_empty(key["key_value"]) then
       break
     end
   end
 
   -- Store the api key for logging.
-  ngx.ctx.api_key = api_key
+  ngx.ctx.api_key = key["key_value"]
 
-  return api_key
+  return key
 end
 
 return function(settings)
   -- Find the API key in the header, query string, or HTTP auth.
   local api_key = resolve_api_key()
-  if is_empty(api_key) then
+  if is_empty(api_key["key_value"]) then
     if settings and settings["disable_api_key"] then
       return nil
     else
@@ -47,7 +62,7 @@ return function(settings)
 
   -- Store the api key on the user object for easier access (the user object
   -- doesn't contain it directly, to save memory storage in the lookup table).
-  user["api_key"] = api_key
+  user["api_key"] = api_key["key_value"]
 
   -- Store user details for logging.
   ngx.ctx.user_id = user["id"]
@@ -76,4 +91,4 @@ return function(settings)
   end
 
   return user
-end
+end
\ No newline at end of file
diff --git a/src/api-umbrella/proxy/user_store.lua b/src/api-umbrella/proxy/user_store.lua
index 6ca87e4e2..6b943af71 100644
--- a/src/api-umbrella/proxy/user_store.lua
+++ b/src/api-umbrella/proxy/user_store.lua
@@ -8,19 +8,33 @@ local mongo = require "api-umbrella.utils.mongo"
 local shcache = require "shcache"
 local types = require "pl.types"
 local utils = require "api-umbrella.proxy.utils"
+local pep = require "api-umbrella.utils.pep"
 
 local cache_computed_settings = utils.cache_computed_settings
 local is_empty = types.is_empty
 
 local function lookup_user(api_key)
-  local raw_user, err = mongo.first("api_users", {
-    query = {
-      api_key = api_key,
-    },
-  })
-
-  if err then
-    ngx.log(ngx.ERR, "failed to fetch user from mongodb: ", err)
+  local raw_user
+  local db_err
+  local pep_err
+
+  -- Checking the field of api_key ["key_type"], if the key_type is api_key
+  -- the api_key value is checked in the database and retrieve the user information
+  -- else if the key_type is token, the token is checked using PEP Proxy and
+  -- the user information is retrieved
+  if not api_key["key_type"] or api_key["key_type"] == "api_key" then
+    raw_user, db_err = mongo.first("api_users", {
+      query = {
+        api_key = api_key["key_value"],
+      },
+    })
+  elseif api_key["key_type"] == "token" then
+    raw_user, pep_err = pep.first(config["gatekeeper"]["pep_host"],config["gatekeeper"]["pep_port"],api_key["key_value"])
+  end
+  if pep_err then
+    ngx.log(ngx.ERR, "failed to autenticate , status code:", pep_err)
+  elseif db_err then
+    ngx.log(ngx.ERR, "failed to fetch user from mongodb", db_err)
   elseif raw_user then
     local user = utils.pick_where_present(raw_user, {
       "created_at",
@@ -36,15 +50,31 @@ local function lookup_user(api_key)
     -- Ensure IDs get stored as strings, even if Mongo ObjectIds are in use.
     if raw_user["_id"] and raw_user["_id"]["$oid"] then
       user["id"] = raw_user["_id"]["$oid"]
+    elseif raw_user.Nick_Name then
+        user["id"] = raw_user.Nick_Name
+        if not raw_user.Email then
+            user["email"] = raw_user.Nick_Name
+        else
+            user["email"] = raw_user.Email
+        end
     else
-      user["id"] = raw_user["_id"]
+        user["id"] = raw_user["_id"]
+    end
+    -- If the validation was made using a token, the Nick_Name associate to the token
+    -- is assigned to the id attribute of the user
+    if raw_user.Nick_Name then
+      user["id"] = raw_user.Nick_Name
     end
 
     -- Invert the array of roles into a hashy table for more optimized
     -- lookups (so we can just check if the key exists, rather than
     -- looping over each value).
+    -- Moreover, in case that the user information have been retrieved using a token validation,
+    -- the roles associated with the token are stored in user ["roles"]
     if user["roles"] then
       user["roles"] = invert_table(user["roles"])
+    elseif raw_user.Roles then
+      user["roles"] = invert_table(raw_user.Roles)
     end
 
     if user["created_at"] and user["created_at"]["$date"] then
@@ -103,14 +133,14 @@ function _M.get(api_key)
     return nil
   end
 
-  user = shared_cache:load(api_key)
+  user = shared_cache:load(api_key["key_value"])
   if user then
-    local_cache:set(api_key, user, 2)
+    local_cache:set(api_key["key_value"], user, 2)
   else
-    local_cache:set(api_key, EMPTY_DATA, 2)
+    local_cache:set(api_key["key_value"], EMPTY_DATA, 2)
   end
 
   return user
 end
 
-return _M
+return _M
\ No newline at end of file
diff --git a/src/api-umbrella/utils/invert_table.lua b/src/api-umbrella/utils/invert_table.lua
index 5d0000f22..126b8f38e 100644
--- a/src/api-umbrella/utils/invert_table.lua
+++ b/src/api-umbrella/utils/invert_table.lua
@@ -1,8 +1,18 @@
 return function(table)
+  local numItems = 0
   local inverted = {}
   for key, value in pairs(table) do
-    inverted[value] = key
+    if type(value)=="string" then
+      inverted[value] = key
+    else
+      for k,v in pairs(value) do
+        numItems = numItems + 1
+      end
+      if numItems > 1 then
+        value = value["name"]
+      end
+      inverted[value] = key
+    end
   end
-
   return inverted
-end
+end
\ No newline at end of file
diff --git a/src/api-umbrella/utils/pep.lua b/src/api-umbrella/utils/pep.lua
new file mode 100644
index 000000000..33e7119d1
--- /dev/null
+++ b/src/api-umbrella/utils/pep.lua
@@ -0,0 +1,27 @@
+local http = require "resty.http"
+local cjson = require "cjson"
+local _M = {}
+-- Function to connect with the Pep Proxy service for checking if the token is valid and retrieve
+-- the user properties. The function takes the PEP Proxy host and port as parameters
+-- and sends a request with the header X-Auth-Token with the value of the token provided
+-- by the user. If the token is valid, PEP proxy sends a response with the user information
+-- asociated to the token, otherwise, it sends a message indicating the result of the
+-- validation process with his status, 404 , 402, etc.
+function _M.first(host, port, token)
+    local result
+    local httpc = http.new()
+    httpc:set_timeout(45000)
+    httpc:connect(host,port)
+    local res, err = httpc:request({headers = {["X-Auth-Token"] = token}})
+    if res and res.status == 200 then
+        local body, body_err = res:read_body()
+        if not body then
+            return nil, body_err
+        end
+        result = cjson.decode(body)
+    end
+
+    return result, err
+end
+
+return _M
\ No newline at end of file