diff --git a/engines/instance_verification/lib/instance_verification/engine.rb b/engines/instance_verification/lib/instance_verification/engine.rb
index 77d52c621..1310b1fbb 100644
--- a/engines/instance_verification/lib/instance_verification/engine.rb
+++ b/engines/instance_verification/lib/instance_verification/engine.rb
@@ -7,13 +7,13 @@ def self.update_cache(remote_ip, system_login, product_id, registry: false)
     unless registry
       InstanceVerification.write_cache_file(
         Rails.application.config.repo_cache_dir,
-        [remote_ip, system_login, product_id].join('-')
+        InstanceVerification.build_cache_key(remote_ip, system_login, base_product_id: product_id)
       )
     end
 
     InstanceVerification.write_cache_file(
       Rails.application.config.registry_cache_dir,
-      [remote_ip, system_login].join('-')
+      InstanceVerification.build_cache_key(remote_ip, system_login)
     )
   end
 
@@ -22,6 +22,73 @@ def self.write_cache_file(cache_dir, cache_key)
     FileUtils.touch(File.join(cache_dir, cache_key))
   end
 
+  def self.verify_instance(request, logger, system)
+    return false unless request.headers['X-Instance-Data']
+
+    instance_data = Base64.decode64(request.headers['X-Instance-Data'].to_s)
+    base_product = system.products.find_by(product_type: 'base')
+    return false unless base_product
+
+    # check the cache for the system (20 min)
+    cache_path = File.join(
+      Rails.application.config.repo_cache_dir,
+      InstanceVerification.build_cache_key(request.remote_ip, system.login, base_product_id: base_product.id)
+    )
+    if File.exist?(cache_path)
+      # only update registry cache key
+      InstanceVerification.update_cache(request.remote_ip, system.login, nil, registry: true)
+      return true
+    end
+
+    verification_provider = InstanceVerification.provider.new(
+      logger,
+      request,
+      base_product.attributes.symbolize_keys.slice(:identifier, :version, :arch, :release_type),
+      instance_data
+    )
+
+    is_valid = verification_provider.instance_valid?
+    # update repository and registry cache
+    InstanceVerification.update_cache(request.remote_ip, system.login, base_product.id)
+    is_valid
+  rescue InstanceVerification::Exception => e
+    message = ''
+    if system.proxy_byos
+      result = SccProxy.scc_check_subscription_expiration(request.headers, system.login, system.system_token, logger)
+      if result[:is_active]
+        InstanceVerification.update_cache(request.remote_ip, system.login, base_product.id)
+        return true
+      end
+
+      message = result[:message]
+    else
+      message = e.message
+    end
+    details = [ "System login: #{system.login}", "IP: #{request.remote_ip}" ]
+    details << "Instance ID: #{verification_provider.instance_id}" if verification_provider.instance_id
+    details << "Billing info: #{verification_provider.instance_billing_info}" if verification_provider.instance_billing_info
+
+    ZypperAuth.auth_logger.info <<~LOGMSG
+    Access to the repos denied: #{message}
+      #{details.join(', ')}
+    LOGMSG
+    false
+  rescue StandardError => e
+    logger.error('Unexpected instance verification error has occurred:')
+    logger.error(e.message)
+    logger.error("System login: #{system.login}, IP: #{request.remote_ip}")
+    logger.error('Backtrace:')
+    logger.error(e.backtrace)
+    false
+  end
+
+  def self.build_cache_key(remote_ip, login, base_product_id: nil)
+    cache_key = [remote_ip, login]
+    cache_key.append(base_product_id) unless base_product_id.nil?
+
+    cache_key.join('-')
+  end
+
   class Engine < ::Rails::Engine
     isolate_namespace InstanceVerification
     config.generators.api_only = true
diff --git a/engines/registry/lib/registry/engine.rb b/engines/registry/lib/registry/engine.rb
index aa5481f12..74dc75022 100644
--- a/engines/registry/lib/registry/engine.rb
+++ b/engines/registry/lib/registry/engine.rb
@@ -15,7 +15,7 @@ class Engine < ::Rails::Engine
         before_action :handle_auth_cache, only: %w[index]
 
         def handle_auth_cache
-          unless ZypperAuth.verify_instance(request, logger, @system)
+          unless InstanceVerification.verify_instance(request, logger, @system)
             render(xml: { error: 'Instance verification failed' }, status: :forbidden)
           end
         end
diff --git a/engines/registry/spec/requests/api/connect/v3/systems/activations_controller_spec.rb b/engines/registry/spec/requests/api/connect/v3/systems/activations_controller_spec.rb
index fced324ea..431288bd6 100644
--- a/engines/registry/spec/requests/api/connect/v3/systems/activations_controller_spec.rb
+++ b/engines/registry/spec/requests/api/connect/v3/systems/activations_controller_spec.rb
@@ -9,7 +9,7 @@
     context 'without valid repository cache' do
       before do
         headers['X-Instance-Data'] = 'IMDS'
-        allow(ZypperAuth).to receive(:verify_instance).and_return(true)
+        allow(InstanceVerification).to receive(:verify_instance).and_return(true)
       end
 
       context 'without X-Instance-Data headers or hw_info' do
@@ -31,7 +31,7 @@
         # allow(File).to receive(:exist?).with("repo/cache/127.0.0.1-#{system.login}-#{system.products.first.id}").and_return(true)
         # allow(File).to receive(:exist?)
         allow(InstanceVerification).to receive(:update_cache)
-        allow(ZypperAuth).to receive(:verify_instance).and_call_original
+        allow(InstanceVerification).to receive(:verify_instance).and_call_original
         headers['X-Instance-Data'] = 'IMDS'
       end
 
diff --git a/engines/zypper_auth/lib/zypper_auth/engine.rb b/engines/zypper_auth/lib/zypper_auth/engine.rb
index 1c87a5de6..78fce5b0f 100644
--- a/engines/zypper_auth/lib/zypper_auth/engine.rb
+++ b/engines/zypper_auth/lib/zypper_auth/engine.rb
@@ -5,66 +5,6 @@ def auth_logger
       Thread.current[:logger].reopen
       Thread.current[:logger]
     end
-
-    def verify_instance(request, logger, system)
-      return false unless request.headers['X-Instance-Data']
-
-      instance_data = Base64.decode64(request.headers['X-Instance-Data'].to_s)
-
-      base_product = system.products.find_by(product_type: 'base')
-      return false unless base_product
-
-      # check the cache for the system (20 min)
-      cache_key = [request.remote_ip, system.login, base_product.id].join('-')
-      cache_path = File.join(Rails.application.config.repo_cache_dir, cache_key)
-      if File.exist?(cache_path)
-        # only update registry cache key
-        InstanceVerification.update_cache(request.remote_ip, system.login, nil, registry: true)
-        return true
-      end
-
-      verification_provider = InstanceVerification.provider.new(
-        logger,
-        request,
-        base_product.attributes.symbolize_keys.slice(:identifier, :version, :arch, :release_type),
-        instance_data
-      )
-
-      is_valid = verification_provider.instance_valid?
-      # update repository and registry cache
-      InstanceVerification.update_cache(request.remote_ip, system.login, base_product.id)
-      is_valid
-    rescue InstanceVerification::Exception => e
-      message = ''
-      if system.proxy_byos
-        result = SccProxy.scc_check_subscription_expiration(request.headers, system.login, system.system_token, logger)
-        if result[:is_active]
-          InstanceVerification.update_cache(request.remote_ip, system.login, base_product.id)
-          return true
-        end
-
-        message = result[:message]
-      else
-        message = e.message
-      end
-      details = [ "System login: #{system.login}", "IP: #{request.remote_ip}" ]
-      details << "Instance ID: #{verification_provider.instance_id}" if verification_provider.instance_id
-      details << "Billing info: #{verification_provider.instance_billing_info}" if verification_provider.instance_billing_info
-
-      ZypperAuth.auth_logger.info <<~LOGMSG
-        Access to the repos denied: #{message}
-        #{details.join(', ')}
-      LOGMSG
-
-      false
-    rescue StandardError => e
-      logger.error('Unexpected instance verification error has occurred:')
-      logger.error(e.message)
-      logger.error("System login: #{system.login}, IP: #{request.remote_ip}")
-      logger.error('Backtrace:')
-      logger.error(e.backtrace)
-      false
-    end
   end
 
   class Engine < ::Rails::Engine
@@ -126,7 +66,7 @@ def make_repo_url(base_url, repo_local_path, service_name = nil)
         # additional validation for zypper service XML controller
         before_action :verify_instance
         def verify_instance
-          unless ZypperAuth.verify_instance(request, logger, @system)
+          unless InstanceVerification.verify_instance(request, logger, @system)
             render(xml: { error: 'Instance verification failed' }, status: 403)
           end
         end
@@ -138,7 +78,7 @@ def verify_instance
         # additional validation for strict_authentication auth subrequest
         def path_allowed?(path)
           return false unless original_path_allowed?(path)
-          ZypperAuth.verify_instance(request, logger, @system)
+          InstanceVerification.verify_instance(request, logger, @system)
         end
       end
     end