diff --git a/.gitignore b/.gitignore
index 0f870d087..96eb56be5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -27,6 +27,7 @@ yarn-debug.log*
 .yarn-integrity
 /.vscode
 /.idea
+/public/assets
 /public/packs
 /public/packs-test
 /node_modules
diff --git a/app/models/bill_signature.rb b/app/models/bill_signature.rb
index 3828c2f1f..8b0e66cf5 100644
--- a/app/models/bill_signature.rb
+++ b/app/models/bill_signature.rb
@@ -92,25 +92,27 @@ class BillSignature < ApplicationRecord
   end
 
   def read_signature
-    if attachment_changes['signature']
-      io = io_for_changes(attachment_changes['signature'])
-      io.read if io.present?
-    elsif signature.attached?
-      signature.download
-    end
+    read_attachment('signature')
   end
 
   def read_serialized
-    if attachment_changes['serialized']
-      io = io_for_changes(attachment_changes['serialized'])
-      io.read if io.present?
+    read_attachment('serialized')
+  end
+
+  private
+
+  def read_attachment(attachment)
+    if attachment_changes[attachment]
+      io = io_for_changes(attachment_changes[attachment])
+      if io.present?
+        io.rewind
+        io.read
+      end
     elsif serialized.attached?
       serialized.download
     end
   end
 
-  private
-
   def io_for_changes(attachment_changes)
     attachable = attachment_changes.attachable
     case attachable
diff --git a/app/models/procedure.rb b/app/models/procedure.rb
index 1f48231c8..e8d970a33 100644
--- a/app/models/procedure.rb
+++ b/app/models/procedure.rb
@@ -568,7 +568,7 @@ class Procedure < ApplicationRecord
     if logo.attached?
       Rails.application.routes.url_helpers.url_for(logo)
     else
-      ActionController::Base.helpers.image_url("republique-francaise-logo.svg")
+      ActionController::Base.helpers.image_url(PROCEDURE_DEFAULT_LOGO_SRC)
     end
   end
 
diff --git a/app/views/new_administrateur/services/_form.html.haml b/app/views/new_administrateur/services/_form.html.haml
index 0e262af20..775577eac 100644
--- a/app/views/new_administrateur/services/_form.html.haml
+++ b/app/views/new_administrateur/services/_form.html.haml
@@ -19,7 +19,7 @@
   %h2.header-section Informations de contact
 
   %p.explication
-    Votre démarche sera hébergée par demarche-simplifiees.fr – mais nous ne pouvons pas assurer le support des démarches. Et malgré la dématérialisation, les usagers se poseront parfois des questions légitimes sur le processus administratif.
+    Votre démarche sera hébergée par #{APPLICATION_NAME} – mais nous ne pouvons pas assurer le support des démarches. Et malgré la dématérialisation, les usagers se poseront parfois des questions légitimes sur le processus administratif.
     %br
     Il est donc important que les usagers puissent vous contacter s'ils ont des questions sur votre démarche.
     %br
diff --git a/config/env.example.optional b/config/env.example.optional
index 96e4e6956..7587634fb 100644
--- a/config/env.example.optional
+++ b/config/env.example.optional
@@ -41,5 +41,8 @@ APPLICATION_BASE_URL="https://www.demarches-simplifiees.fr"
 # Personnalisation d'instance - Logo dans l'entête des emails ---> à placer dans "app/assets/images"
 # MAILER_LOGO_SRC="mailer/instructeur_mailer/logo.png"
 
+# Personnalisation d'instance - Logo par défaut d'une procédure  ---> à placer dans "app/assets/images"
+# PROCEDURE_DEFAULT_LOGO_SRC="republique-francaise-logo.svg"
+
 # Personnalisation d'instance - fichier utilisé pour poser un filigrane sur les pièces d'identité
 # WATERMARK_FILE=""
diff --git a/config/initializers/images.rb b/config/initializers/images.rb
index d8415c742..628857d42 100644
--- a/config/initializers/images.rb
+++ b/config/initializers/images.rb
@@ -11,3 +11,6 @@ HEADER_LOGO_HEIGHT = ENV.fetch("HEADER_LOGO_HEIGHT", "56")
 
 # Mailer logo
 MAILER_LOGO_SRC = ENV.fetch("MAILER_LOGO_SRC", "mailer/instructeur_mailer/logo.png")
+
+# Default logo of a procedure
+PROCEDURE_DEFAULT_LOGO_SRC = ENV.fetch("PROCEDURE_DEFAULT_LOGO_SRC", "republique-francaise-logo.svg")
diff --git a/spec/models/bill_signature_spec.rb b/spec/models/bill_signature_spec.rb
index a31c399e6..a8d64a2fd 100644
--- a/spec/models/bill_signature_spec.rb
+++ b/spec/models/bill_signature_spec.rb
@@ -72,48 +72,41 @@ RSpec.describe BillSignature, type: :model do
     end
 
     describe 'check_signature_contents' do
+      let(:signature) { File.open('spec/fixtures/files/bill_signature/signature.der') }
+      let(:signature_date) { DateTime.parse('2019-04-30 15:30:20') }
+      let(:signature_digest) { Digest::SHA256.hexdigest('CECI EST UN BLOB') }
+      let(:current_date) { Time.zone.now }
+
       before do
-        bill_signature.signature.attach(io: StringIO.new(signature), filename: 'file') if signature.present?
-        allow(ASN1::Timestamp).to receive(:signature_time).and_return(signature_time)
-        allow(ASN1::Timestamp).to receive(:signed_digest).and_return(signed_digest)
-        bill_signature.digest = digest
+        Timecop.freeze(current_date)
+        bill_signature.signature.attach(io: signature, filename: 'file') if signature.present?
+        bill_signature.digest = signature_digest
         bill_signature.valid?
+        Timecop.return
       end
 
-      context 'when the signature is correct' do
-        let(:signature) { 'signature' }
-        let(:signature_time) { 1.day.ago }
-        let(:digest) { 'abcd' }
-        let(:signed_digest) { 'abcd' }
+      subject { bill_signature.errors.details[:signature] }
 
-        it { expect(bill_signature.errors.details[:signature]).to be_empty }
+      context 'when the signature is correct' do
+        it { is_expected.to be_empty }
       end
 
       context 'when the signature isn’t set' do
         let(:signature) { nil }
-        let(:signature_time) { 1.day.ago }
-        let(:digest) { 'abcd' }
-        let(:signed_digest) { 'abcd' }
 
-        it { expect(bill_signature.errors.details[:signature]).to eq [error: :blank] }
+        it { is_expected.to eq [error: :blank] }
       end
 
       context 'when the signature time is in the future' do
-        let(:signature) { 'signature' }
-        let(:signature_time) { 1.day.from_now }
-        let(:digest) { 'abcd' }
-        let(:signed_digest) { 'abcd' }
+        let(:current_date) { signature_date - 1.day }
 
-        it { expect(bill_signature.errors.details[:signature]).to eq [error: :invalid_date] }
+        it { is_expected.to eq [error: :invalid_date] }
       end
 
       context 'when the signature doesn’t match the digest' do
-        let(:signature) { 'signature' }
-        let(:signature_time) { 1.day.ago }
-        let(:digest) { 'abcd' }
-        let(:signed_digest) { 'dcba' }
+        let(:signature_digest) { 'dcba' }
 
-        it { expect(bill_signature.errors.details[:signature]).to eq [error: :invalid] }
+        it { is_expected.to eq [error: :invalid] }
       end
     end
   end