diff --git a/app/models/post.rb b/app/models/post.rb
index 8b851ad..25beb7f 100644
--- a/app/models/post.rb
+++ b/app/models/post.rb
@@ -11,7 +11,7 @@ class Post < OpenStruct
   DEFAULT_ATTRIBUTES = %i[site document layout].freeze
   # Otros atributos que no vienen en los metadatos
   PRIVATE_ATTRIBUTES = %i[path slug attributes errors].freeze
-  PUBLIC_ATTRIBUTES = %i[lang date].freeze
+  PUBLIC_ATTRIBUTES = %i[lang date uuid].freeze
 
   class << self
     # Obtiene el layout sin leer el Document
@@ -63,18 +63,20 @@ class Post < OpenStruct
     load_slug!
     load_date!
     load_path!
+    load_uuid!
 
     # XXX: No usamos Post#read porque a esta altura todavía no sabemos
     # nada del Document
     document.read! if File.exist? document.path
   end
 
+  # TODO: Convertir a UUID?
   def id
     path.basename
   end
 
-  def sha1
-    Digest::SHA1.hexdigest id
+  def updated_at
+    File.mtime(path.absolute)
   end
 
 
@@ -142,8 +144,10 @@ class Post < OpenStruct
       { metadata.to_s => template.value }
     end.compact.inject(:merge)
 
+    # TODO: Convertir a Metadata?
     # Asegurarse que haya un layout
     yaml['layout'] = layout.name.to_s
+    yaml['uuid'] = uuid.value
     # Y que no se procese liquid
     yaml['liquid'] = false
     yaml['usuaries'] = usuaries.map(&:id).uniq
@@ -335,6 +339,13 @@ class Post < OpenStruct
                                  required: true)
   end
 
+  def load_uuid!
+    self.uuid = MetadataUuid.new(document: document, site: site,
+                                 layout: layout, name: :uuid,
+                                 type: :uuid, post: self,
+                                 required: true)
+  end
+
   # Ejecuta la acción de guardado en cada atributo
   def save_attributes!
     attributes.map do |attr|
diff --git a/app/models/post_relation.rb b/app/models/post_relation.rb
index 934b2c5..e262893 100644
--- a/app/models/post_relation.rb
+++ b/app/models/post_relation.rb
@@ -56,10 +56,14 @@ class PostRelation < Array
 
   alias find_generic find
 
-  # Encontra un post por su id convertido a SHA1
-  def find(id, sha1: false)
+  # Encontrar un post por su UUID
+  def find(id, uuid: false)
     find_generic do |p|
-      p.sha1 == (sha1 ? id : Digest::SHA1.hexdigest(id))
+      if uuid
+        p.uuid.value == id
+      else
+        p.id == id
+      end
     end
   end
 
diff --git a/app/services/post_service.rb b/app/services/post_service.rb
index b97a3fd..1745290 100644
--- a/app/services/post_service.rb
+++ b/app/services/post_service.rb
@@ -40,18 +40,18 @@ PostService = Struct.new(:site, :usuarie, :post, :params, keyword_init: true) do
   end
 
   # Reordena todos los posts que soporten orden de acuerdo a un hash de
-  # ids y nuevas posiciones.  La posición actual la da la posición en
+  # uuids y nuevas posiciones.  La posición actual la da la posición en
   # el array.
   #
-  # { sha1 => 2, sha1 => 1, sha1 => 0 }
+  # { uuid => 2, uuid => 1, uuid => 0 }
   def reorder
     posts = site.posts(lang: lang)
     reorder = params.require(:post).permit(reorder: {}).try(:[], :reorder)
     modified = PostRelation.new(site: site)
 
-    files = reorder.keys.map do |id|
-      post = posts.find(id, sha1: true)
-      order = reorder[id].to_i
+    files = reorder.keys.map do |uuid|
+      post = posts.find(uuid, uuid: true)
+      order = reorder[uuid].to_i
 
       next unless post.attributes.include? :order
       next if post.order.value == order
diff --git a/app/views/posts/attribute_ro/_uuid.haml b/app/views/posts/attribute_ro/_uuid.haml
new file mode 100644
index 0000000..31dd8f0
--- /dev/null
+++ b/app/views/posts/attribute_ro/_uuid.haml
@@ -0,0 +1,3 @@
+%tr{ id: attribute }
+  %th= post_label_t(attribute, post: post)
+  %td= metadata.value
diff --git a/app/views/posts/attributes/_uuid.haml b/app/views/posts/attributes/_uuid.haml
new file mode 100644
index 0000000..0aab980
--- /dev/null
+++ b/app/views/posts/attributes/_uuid.haml
@@ -0,0 +1 @@
+-# nada
diff --git a/app/views/posts/index.haml b/app/views/posts/index.haml
index eab3933..7e0ce3a 100644
--- a/app/views/posts/index.haml
+++ b/app/views/posts/index.haml
@@ -48,7 +48,7 @@
                   .handle
                     = image_tag 'arrows-alt-v.svg'
                   -# Orden más alto es mayor prioridad
-                  = hidden_field 'post[reorder]', post.sha1,
+                  = hidden_field 'post[reorder]', post.uuid.value,
                     value: @posts.length - i, class: 'reorder'
                 %td
                   %small
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 84215d0..4e0d1c8 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -348,6 +348,8 @@ en:
       required:
         label: ' (required)'
         feedback: 'This field cannot be empty!'
+      uuid:
+        label: 'Unique identifier'
     reorder: 'Reorder posts'
     sort:
       by: 'Sort by'
diff --git a/config/locales/es.yml b/config/locales/es.yml
index 2c71813..3a11551 100644
--- a/config/locales/es.yml
+++ b/config/locales/es.yml
@@ -358,6 +358,8 @@ es:
       required:
         label: ' (requerido)'
         feedback: '¡Este campo no puede estar vacío!'
+      uuid:
+        label: 'Identificador único'
     reorder: 'Reordenar artículos'
     sort:
       by: 'Ordenar por'
diff --git a/test/controllers/posts_controller_test.rb b/test/controllers/posts_controller_test.rb
index 3075948..6a25fe3 100644
--- a/test/controllers/posts_controller_test.rb
+++ b/test/controllers/posts_controller_test.rb
@@ -145,7 +145,7 @@ class PostsControllerTest < ActionDispatch::IntegrationTest
   test 'se pueden reordenar' do
     lang = I18n.available_locales.sample
     posts = @site.posts(lang: lang)
-    reorder = Hash[posts.map(&:sha1).shuffle.each_with_index.to_a]
+    reorder = Hash[posts.map { |p| p.uuid.value }.shuffle.each_with_index.to_a]
 
     post site_posts_reorder_url(@site),
          headers: @authorization,
@@ -157,7 +157,7 @@ class PostsControllerTest < ActionDispatch::IntegrationTest
                  @site.repository.rugged.head.target.message
     assert_equal reorder,
                  Hash[@site.posts(lang: lang).map do |p|
-                   [p.sha1, p.order.value]
+                   [p.uuid.value, p.order.value]
                  end]
   end
 end