diff --git a/config/feature_flags/development/ci_secure_files.yml b/config/feature_flags/development/ci_secure_files.yml
new file mode 100644
index 0000000000000000000000000000000000000000..a1aa82fe298432a4ae503634ecd6441dab49741d
--- /dev/null
+++ b/config/feature_flags/development/ci_secure_files.yml
@@ -0,0 +1,8 @@
+---
+name: ci_secure_files
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/78227
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/350748
+milestone: '14.8'
+type: development
+group: group::incubation
+default_enabled: false
diff --git a/config/gitlab.yml.example b/config/gitlab.yml.example
index f5755591da731e65fa7f2a57e5d22d59f55193c1..632f077f4a6f0c4d7ebfd41f6577eae87fabfba3 100644
--- a/config/gitlab.yml.example
+++ b/config/gitlab.yml.example
@@ -404,6 +404,23 @@ production: &base
         # aws_signature_version: 4 # For creation of signed URLs. Set to 2 if provider does not support v4.
         # path_style: true # Use 'host/bucket_name/object' instead of 'bucket_name.host/object'
 
+  ## CI Secure Files
+  ci_secure_files:
+    enabled: true
+    # storage_path: shared/ci_secure_files
+    object_store:
+      enabled: false
+      remote_directory: ci_secure_files # The bucket name
+      connection:
+        provider: AWS
+        aws_access_key_id: AWS_ACCESS_KEY_ID
+        aws_secret_access_key: AWS_SECRET_ACCESS_KEY
+        region: us-east-1
+        # host: 'localhost' # default: s3.amazonaws.com
+        # endpoint: 'http://127.0.0.1:9000' # default: nil
+        # aws_signature_version: 4 # For creation of signed URLs. Set to 2 if provider does not support v4.
+        # path_style: true # Use 'host/bucket_name/object' instead of 'bucket_name.host/object'
+
   ## GitLab Pages
   pages:
     enabled: false
diff --git a/lib/api/api.rb b/lib/api/api.rb
index 5984879413f2606a4c0e54192334c5f811ca1c09..bfd070ba6da0e44a0c4b8f6932efa32c0d8f95f9 100644
--- a/lib/api/api.rb
+++ b/lib/api/api.rb
@@ -171,6 +171,7 @@ class API < ::API::Base
       mount ::API::Ci::ResourceGroups
       mount ::API::Ci::Runner
       mount ::API::Ci::Runners
+      mount ::API::Ci::SecureFiles
       mount ::API::Ci::Triggers
       mount ::API::Ci::Variables
       mount ::API::Commits
diff --git a/lib/api/ci/secure_files.rb b/lib/api/ci/secure_files.rb
new file mode 100644
index 0000000000000000000000000000000000000000..715a8b37fae2ba9e710d545cde5cabef38d60189
--- /dev/null
+++ b/lib/api/ci/secure_files.rb
@@ -0,0 +1,98 @@
+# frozen_string_literal: true
+
+module API
+  module Ci
+    class SecureFiles < ::API::Base
+      include PaginationParams
+
+      before do
+        authenticate!
+        authorize! :admin_build, user_project
+        feature_flag_enabled?
+      end
+
+      feature_category :pipeline_authoring
+
+      default_format :json
+
+      params do
+        requires :id, type: String, desc: 'The ID of a project'
+      end
+
+      resource :projects, requirements: API::NAMESPACE_OR_PROJECT_REQUIREMENTS do
+        desc 'List all Secure Files for a Project'
+        params do
+          use :pagination
+        end
+        route_setting :authentication, basic_auth_personal_access_token: true, job_token_allowed: true
+        get ':id/secure_files' do
+          secure_files = user_project.secure_files
+          present paginate(secure_files), with: Entities::Ci::SecureFile
+        end
+
+        desc 'Get an individual Secure File'
+        params do
+          requires :id, type: Integer, desc: 'The Secure File ID'
+        end
+
+        route_setting :authentication, basic_auth_personal_access_token: true, job_token_allowed: true
+        get ':id/secure_files/:secure_file_id' do
+          secure_file = user_project.secure_files.find(params[:secure_file_id])
+          present secure_file, with: Entities::Ci::SecureFile
+        end
+
+        desc 'Download a Secure File'
+        route_setting :authentication, basic_auth_personal_access_token: true, job_token_allowed: true
+        get ':id/secure_files/:secure_file_id/download' do
+          secure_file = user_project.secure_files.find(params[:secure_file_id])
+
+          content_type 'application/octet-stream'
+          env['api.format'] = :binary
+          header['Content-Disposition'] = "attachment; filename=#{secure_file.name}"
+          body secure_file.file.read
+        end
+
+        desc 'Upload a Secure File'
+        params do
+          requires :name, type: String, desc: 'The name of the file'
+          requires :file, types: [Rack::Multipart::UploadedFile, ::API::Validations::Types::WorkhorseFile], desc: 'The secure file to be uploaded'
+          optional :permissions, type: String, desc: 'The file permissions', default: 'read_only', values: %w[read_only read_write execute]
+        end
+
+        route_setting :authentication, basic_auth_personal_access_token: true, job_token_allowed: true
+        post ':id/secure_files' do
+          secure_file = user_project.secure_files.new(
+            name: params[:name],
+            permissions: params[:permissions] || :read_only
+          )
+
+          secure_file.file = params[:file]
+
+          file_too_large! unless secure_file.file.size < ::Ci::SecureFile::FILE_SIZE_LIMIT.to_i
+
+          if secure_file.save
+            present secure_file, with: Entities::Ci::SecureFile
+          else
+            render_validation_error!(secure_file)
+          end
+        end
+
+        desc 'Delete an individual Secure File'
+        route_setting :authentication, basic_auth_personal_access_token: true, job_token_allowed: true
+        delete ':id/secure_files/:secure_file_id' do
+          secure_file = user_project.secure_files.find(params[:secure_file_id])
+
+          secure_file.destroy!
+
+          no_content!
+        end
+      end
+
+      helpers do
+        def feature_flag_enabled?
+          service_unavailable! unless Feature.enabled?(:ci_secure_files, user_project, default_enabled: :yaml)
+        end
+      end
+    end
+  end
+end
diff --git a/lib/api/entities/ci/secure_file.rb b/lib/api/entities/ci/secure_file.rb
new file mode 100644
index 0000000000000000000000000000000000000000..041c864156b4639ea31c7e2765ad42b38c2fb7db
--- /dev/null
+++ b/lib/api/entities/ci/secure_file.rb
@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+module API
+  module Entities
+    module Ci
+      class SecureFile < Grape::Entity
+        expose :id
+        expose :name
+        expose :permissions
+        expose :checksum
+        expose :checksum_algorithm
+      end
+    end
+  end
+end
diff --git a/spec/requests/api/ci/secure_files_spec.rb b/spec/requests/api/ci/secure_files_spec.rb
new file mode 100644
index 0000000000000000000000000000000000000000..5cf6999f60a1e360549099455bf8a5823a358e90
--- /dev/null
+++ b/spec/requests/api/ci/secure_files_spec.rb
@@ -0,0 +1,314 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe API::Ci::SecureFiles do
+  before do
+    stub_ci_secure_file_object_storage
+    stub_feature_flags(ci_secure_files: true)
+  end
+
+  let_it_be(:user) { create(:user) }
+  let_it_be(:user2) { create(:user) }
+  let_it_be(:project) { create(:project, creator_id: user.id) }
+  let_it_be(:maintainer) { create(:project_member, :maintainer, user: user, project: project) }
+  let_it_be(:developer) { create(:project_member, :developer, user: user2, project: project) }
+  let_it_be(:secure_file) { create(:ci_secure_file, project: project) }
+
+  describe 'GET /projects/:id/secure_files' do
+    context 'feature flag' do
+      it 'returns a 503 when the feature flag is disabled' do
+        stub_feature_flags(ci_secure_files: false)
+
+        get api("/projects/#{project.id}/secure_files", user)
+
+        expect(response).to have_gitlab_http_status(:service_unavailable)
+      end
+
+      it 'returns a 200 when the feature flag is enabled' do
+        get api("/projects/#{project.id}/secure_files", user)
+
+        expect(response).to have_gitlab_http_status(:ok)
+        expect(json_response).to be_a(Array)
+      end
+    end
+
+    context 'authorized user with proper permissions' do
+      it 'returns project secure files' do
+        get api("/projects/#{project.id}/secure_files", user)
+
+        expect(response).to have_gitlab_http_status(:ok)
+        expect(json_response).to be_a(Array)
+      end
+    end
+
+    context 'authorized user with invalid permissions' do
+      it 'does not return project secure files' do
+        get api("/projects/#{project.id}/secure_files", user2)
+
+        expect(response).to have_gitlab_http_status(:forbidden)
+      end
+    end
+
+    context 'unauthorized user' do
+      it 'does not return project secure files' do
+        get api("/projects/#{project.id}/secure_files")
+
+        expect(response).to have_gitlab_http_status(:unauthorized)
+      end
+    end
+  end
+
+  describe 'GET /projects/:id/secure_files/:secure_file_id' do
+    context 'authorized user with proper permissions' do
+      it 'returns project secure file details' do
+        get api("/projects/#{project.id}/secure_files/#{secure_file.id}", user)
+
+        expect(response).to have_gitlab_http_status(:ok)
+        expect(json_response['name']).to eq(secure_file.name)
+        expect(json_response['permissions']).to eq(secure_file.permissions)
+      end
+
+      it 'responds with 404 Not Found if requesting non-existing secure file' do
+        get api("/projects/#{project.id}/secure_files/99999", user)
+
+        expect(response).to have_gitlab_http_status(:not_found)
+      end
+    end
+
+    context 'authorized user with invalid permissions' do
+      it 'does not return project secure file details' do
+        get api("/projects/#{project.id}/secure_files/#{secure_file.id}", user2)
+
+        expect(response).to have_gitlab_http_status(:forbidden)
+      end
+    end
+
+    context 'unauthorized user' do
+      it 'does not return project secure file details' do
+        get api("/projects/#{project.id}/secure_files/#{secure_file.id}")
+
+        expect(response).to have_gitlab_http_status(:unauthorized)
+      end
+    end
+  end
+
+  describe 'GET /projects/:id/secure_files/:secure_file_id/download' do
+    context 'authorized user with proper permissions' do
+      it 'returns a secure file' do
+        sample_file = fixture_file('ci_secure_files/upload-keystore.jks')
+        secure_file.file = CarrierWaveStringFile.new(sample_file)
+        secure_file.save!
+
+        get api("/projects/#{project.id}/secure_files/#{secure_file.id}/download", user)
+
+        expect(response).to have_gitlab_http_status(:ok)
+        expect(Base64.encode64(response.body)).to eq(Base64.encode64(sample_file))
+      end
+
+      it 'responds with 404 Not Found if requesting non-existing secure file' do
+        get api("/projects/#{project.id}/secure_files/99999/download", user)
+
+        expect(response).to have_gitlab_http_status(:not_found)
+      end
+    end
+
+    context 'authorized user with invalid permissions' do
+      it 'does not return project secure file details' do
+        get api("/projects/#{project.id}/secure_files/#{secure_file.id}/download", user2)
+
+        expect(response).to have_gitlab_http_status(:forbidden)
+      end
+    end
+
+    context 'unauthorized user' do
+      it 'does not return project secure file details' do
+        get api("/projects/#{project.id}/secure_files/#{secure_file.id}/download")
+
+        expect(response).to have_gitlab_http_status(:unauthorized)
+      end
+    end
+  end
+
+  describe 'POST /projects/:id/secure_files' do
+    context 'authorized user with proper permissions' do
+      it 'creates a secure file' do
+        params = {
+          file: fixture_file_upload('spec/fixtures/ci_secure_files/upload-keystore.jks'),
+          name: 'upload-keystore.jks',
+          permissions: 'execute'
+        }
+
+        expect do
+          post api("/projects/#{project.id}/secure_files", user), params: params
+        end.to change {project.secure_files.count}.by(1)
+
+        expect(response).to have_gitlab_http_status(:created)
+        expect(json_response['name']).to eq('upload-keystore.jks')
+        expect(json_response['permissions']).to eq('execute')
+        expect(json_response['checksum']).to eq(secure_file.checksum)
+        expect(json_response['checksum_algorithm']).to eq('sha256')
+
+        secure_file = Ci::SecureFile.find(json_response['id'])
+        expect(secure_file.checksum).to eq(
+          Digest::SHA256.hexdigest(fixture_file('ci_secure_files/upload-keystore.jks'))
+        )
+        expect(json_response['id']).to eq(secure_file.id)
+      end
+
+      it 'creates a secure file with read_only permissions by default' do
+        params = {
+          file: fixture_file_upload('spec/fixtures/ci_secure_files/upload-keystore.jks'),
+          name: 'upload-keystore.jks'
+        }
+
+        expect do
+          post api("/projects/#{project.id}/secure_files", user), params: params
+        end.to change {project.secure_files.count}.by(1)
+
+        expect(json_response['permissions']).to eq('read_only')
+      end
+
+      it 'uploads and downloads a secure file' do
+        post_params = {
+          file: fixture_file_upload('spec/fixtures/ci_secure_files/upload-keystore.jks'),
+          name: 'upload-keystore.jks',
+          permissions: 'read_write'
+        }
+
+        post api("/projects/#{project.id}/secure_files", user), params: post_params
+
+        secure_file_id = json_response['id']
+
+        get api("/projects/#{project.id}/secure_files/#{secure_file_id}/download", user)
+
+        expect(Base64.encode64(response.body)).to eq(Base64.encode64(fixture_file_upload('spec/fixtures/ci_secure_files/upload-keystore.jks').read))
+      end
+
+      it 'returns an error when the file checksum fails to validate' do
+        secure_file.update!(checksum: 'foo')
+
+        get api("/projects/#{project.id}/secure_files/#{secure_file.id}/download", user)
+
+        expect(response.code).to eq("500")
+      end
+
+      it 'returns an error when no file is uploaded' do
+        post_params = {
+          name: 'upload-keystore.jks'
+        }
+
+        post api("/projects/#{project.id}/secure_files", user), params: post_params
+
+        expect(response).to have_gitlab_http_status(:bad_request)
+        expect(json_response['error']).to eq('file is missing')
+      end
+
+      it 'returns an error when the file name is missing' do
+        post_params = {
+          file: fixture_file_upload('spec/fixtures/ci_secure_files/upload-keystore.jks')
+        }
+
+        post api("/projects/#{project.id}/secure_files", user), params: post_params
+
+        expect(response).to have_gitlab_http_status(:bad_request)
+        expect(json_response['error']).to eq('name is missing')
+      end
+
+      it 'returns an error when an unexpected permission is supplied' do
+        post_params = {
+          file: fixture_file_upload('spec/fixtures/ci_secure_files/upload-keystore.jks'),
+          name: 'upload-keystore.jks',
+          permissions: 'foo'
+        }
+
+        post api("/projects/#{project.id}/secure_files", user), params: post_params
+
+        expect(response).to have_gitlab_http_status(:bad_request)
+        expect(json_response['error']).to eq('permissions does not have a valid value')
+      end
+
+      it 'returns an error when an unexpected validation failure happens' do
+        allow_next_instance_of(Ci::SecureFile) do |instance|
+          allow(instance).to receive(:valid?).and_return(false)
+          allow(instance).to receive_message_chain(:errors, :any?).and_return(true)
+          allow(instance).to receive_message_chain(:errors, :messages).and_return(['Error 1', 'Error 2'])
+        end
+
+        post_params = {
+          file: fixture_file_upload('spec/fixtures/ci_secure_files/upload-keystore.jks'),
+          name: 'upload-keystore.jks'
+        }
+
+        post api("/projects/#{project.id}/secure_files", user), params: post_params
+
+        expect(response).to have_gitlab_http_status(:bad_request)
+      end
+
+      it 'returns a 413 error when the file size is too large' do
+        allow_next_instance_of(Ci::SecureFile) do |instance|
+          allow(instance).to receive_message_chain(:file, :size).and_return(6.megabytes.to_i)
+        end
+
+        post_params = {
+          file: fixture_file_upload('spec/fixtures/ci_secure_files/upload-keystore.jks'),
+          name: 'upload-keystore.jks'
+        }
+
+        post api("/projects/#{project.id}/secure_files", user), params: post_params
+
+        expect(response).to have_gitlab_http_status(:payload_too_large)
+      end
+    end
+
+    context 'authorized user with invalid permissions' do
+      it 'does not create a secure file' do
+        post api("/projects/#{project.id}/secure_files", user2)
+
+        expect(response).to have_gitlab_http_status(:forbidden)
+      end
+    end
+
+    context 'unauthorized user' do
+      it 'does not create a secure file' do
+        post api("/projects/#{project.id}/secure_files")
+
+        expect(response).to have_gitlab_http_status(:unauthorized)
+      end
+    end
+  end
+
+  describe 'DELETE /projects/:id/secure_files/:secure_file_id' do
+    context 'authorized user with proper permissions' do
+      it 'deletes the secure file' do
+        expect do
+          delete api("/projects/#{project.id}/secure_files/#{secure_file.id}", user)
+
+          expect(response).to have_gitlab_http_status(:no_content)
+        end.to change {project.secure_files.count}.by(-1)
+      end
+
+      it 'responds with 404 Not Found if requesting non-existing secure_file' do
+        delete api("/projects/#{project.id}/secure_files/99999", user)
+
+        expect(response).to have_gitlab_http_status(:not_found)
+      end
+    end
+
+    context 'authorized user with invalid permissions' do
+      it 'does not delete the secure_file' do
+        delete api("/projects/#{project.id}/secure_files/#{secure_file.id}", user2)
+
+        expect(response).to have_gitlab_http_status(:forbidden)
+      end
+    end
+
+    context 'unauthorized user' do
+      it 'does not delete the secure_file' do
+        delete api("/projects/#{project.id}/secure_files/#{secure_file.id}")
+
+        expect(response).to have_gitlab_http_status(:unauthorized)
+      end
+    end
+  end
+end