diff --git a/lib/generators/rubykassa/templates/rubykassa.rb b/lib/generators/rubykassa/templates/rubykassa.rb
index 0fe90ac..7add41e 100644
--- a/lib/generators/rubykassa/templates/rubykassa.rb
+++ b/lib/generators/rubykassa/templates/rubykassa.rb
@@ -1,10 +1,11 @@
 Rubykassa.configure do |config|
-  config.login = ENV["ROBOKASSA_LOGIN"]
-  config.first_password = ENV["ROBOKASSA_FIRST_PASSWORD"]
-  config.second_password = ENV["ROBOKASSA_SECOND_PASSWORD"]
+  config.login = ENV['ROBOKASSA_LOGIN']
+  config.first_password = ENV['ROBOKASSA_FIRST_PASSWORD']
+  config.second_password = ENV['ROBOKASSA_SECOND_PASSWORD']
   config.mode = :test # or :production
   config.http_method = :get # or :post
   config.xml_http_method = :get # or :post
+  config.hash_algorithm = :md5 # or :ripemd160, :sha1, :sha256, :sha384, :sha512
 
 
   # Result callback is called in RobokassaController#result action if valid signature
diff --git a/lib/rubykassa/client.rb b/lib/rubykassa/client.rb
index 0d2ed0f..a70489a 100644
--- a/lib/rubykassa/client.rb
+++ b/lib/rubykassa/client.rb
@@ -6,6 +6,10 @@ class ConfigurationError < StandardError
       'Invalid mode: only :test or :production are allowed'.freeze
     HTTP_METHOD_MESSAGE =
       'Invalid http method: only :get or :post are allowed'.freeze
+    HASH_ALGORITHM_MESSAGE = <<-MESSAGE.squish.freeze
+      Invalid hash algorithm: only
+      #{Configuration::HASH_ALGORITHMS.map(&:upcase).join ', '} are allowed
+    MESSAGE
 
     def self.raise_errors_for(configuration)
       if !configuration.correct_mode?
@@ -15,6 +19,9 @@ def self.raise_errors_for(configuration)
           !configuration.correct_xml_http_method?
         raise ConfigurationError, HTTP_METHOD_MESSAGE
       end
+      if !configuration.correct_hash_algorithm?
+        raise ConfigurationError, HASH_ALGORITHM_MESSAGE
+      end
     end
   end
 
diff --git a/lib/rubykassa/configuration.rb b/lib/rubykassa/configuration.rb
index 1195730..5550149 100644
--- a/lib/rubykassa/configuration.rb
+++ b/lib/rubykassa/configuration.rb
@@ -2,8 +2,10 @@ module Rubykassa
   class Configuration
     ATTRIBUTES = [
       :login, :first_password, :second_password, :mode, :http_method,
-      :xml_http_method, :success_callback, :fail_callback, :result_callback
+      :xml_http_method, :success_callback, :fail_callback, :result_callback,
+      :hash_algorithm
     ]
+    HASH_ALGORITHMS = [:md5, :ripemd160, :sha1, :sha256, :sha384, :sha512]
 
     attr_accessor *ATTRIBUTES
 
@@ -14,6 +16,7 @@ def initialize
       self.mode             = :test
       self.http_method      = :get
       self.xml_http_method  = :get
+      self.hash_algorithm   = :md5
       self.success_callback = ->(notification) { render text: 'success' }
       self.fail_callback    = ->(notification) { render text: 'fail' }
       self.result_callback  = ->(notification) do
@@ -32,5 +35,9 @@ def correct_http_method?
     def correct_xml_http_method?
       [:get, :post].include?(xml_http_method)
     end
+
+    def correct_hash_algorithm?
+      HASH_ALGORITHMS.include?(hash_algorithm)
+    end
   end
 end
diff --git a/lib/rubykassa/signature_generator.rb b/lib/rubykassa/signature_generator.rb
index a82a7cb..e8d0776 100644
--- a/lib/rubykassa/signature_generator.rb
+++ b/lib/rubykassa/signature_generator.rb
@@ -7,7 +7,7 @@ def generate_signature_for(kind)
       unless [:success, :payment, :result].include?(kind)
         raise ArgumentError, KIND_ERROR_MESSAGE
       end
-      Digest::MD5.hexdigest(params_string(kind))
+      method(Rubykassa.hash_algorithm).call params_string(kind)
     end
 
     def params_string kind
@@ -29,5 +29,31 @@ def custom_params
         result
       end
     end
+
+    protected
+
+    def md5(data)
+      Digest::MD5.hexdigest data
+    end
+
+    def ripemd160(data)
+      Digest::RMD160.hexdigest data
+    end
+
+    def sha1(data)
+      Digest::SHA1.hexdigest data
+    end
+
+    def sha265(data)
+      Digest::SHA256.hexdigest data
+    end
+
+    def sha384(data)
+      Digest::SHA384.hexdigest data
+    end
+
+    def sha512(data)
+      Digest::SHA512.hexdigest data
+    end
   end
 end
diff --git a/spec/rubykassa/client_configuration_spec.rb b/spec/rubykassa/client_configuration_spec.rb
index e660849..5959853 100644
--- a/spec/rubykassa/client_configuration_spec.rb
+++ b/spec/rubykassa/client_configuration_spec.rb
@@ -9,6 +9,7 @@
       config.mode = :production
       config.http_method = :post
       config.xml_http_method = :post
+      config.hash_algorithm = :md5
     end
   end
 
@@ -29,7 +30,8 @@
     expect(Rubykassa.second_password).to eq 'second_password'
     expect(Rubykassa.mode).to eq :test
     expect(Rubykassa.http_method).to eq :get
-    expect(Rubykassa.http_method).to eq :get
+    expect(Rubykassa.xml_http_method).to eq :get
+    expect(Rubykassa.hash_algorithm).to eq :md5
     expect(Rubykassa.success_callback).to be_instance_of(Proc)
     expect(Rubykassa.fail_callback).to be_instance_of(Proc)
   end
@@ -67,4 +69,13 @@
     }.to raise_error(Rubykassa::ConfigurationError,
                      Rubykassa::ConfigurationError::HTTP_METHOD_MESSAGE)
   end
+
+  it 'should raise error when wrong hash_algorithms is set' do
+    expect {
+      Rubykassa.configure do |config|
+        config.hash_algorithm = :bullshit
+      end
+    }.to raise_error(Rubykassa::ConfigurationError,
+                     Rubykassa::ConfigurationError::HASH_ALGORITHM_MESSAGE)
+  end
 end
diff --git a/spec/rubykassa/notification_spec.rb b/spec/rubykassa/notification_spec.rb
index 6e8f509..05a1b61 100644
--- a/spec/rubykassa/notification_spec.rb
+++ b/spec/rubykassa/notification_spec.rb
@@ -1,6 +1,11 @@
 require 'spec_helper'
 
 describe Rubykassa::Notification do
+  before(:each) do
+    Rubykassa.configure do |config|
+    end
+  end
+
   it 'should return correct valid_result_signature?' do
     params = { 'InvId' => '12',
                'OutSum' => '1200',