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For most apps Sha512 is plenty secure, but if you are building an app that stores nuclear launch codes you might want to consier BCrypt. This is an extremely secure hashing algorithm, mainly because it is slow. A brute force attack on a BCrypt encrypted password would take much longer than a brute force attack on a password encrypted with a Sha algorithm. Keep in mind you are sacrificing performance by using this, generating a password takes exponentially longer than any of the Sha algorithms. I did some benchmarking to save you some time with your decision:
require "bcrypt" require "digest" require "benchmark" Benchmark.bm(18) do |x| x.report("BCrypt (cost = 10:") { 100.times { BCrypt::Password.create("mypass", :cost => 10) } } x.report("BCrypt (cost = 4:") { 100.times { BCrypt::Password.create("mypass", :cost => 4) } } x.report("Sha512:") { 100.times { Digest::SHA512.hexdigest("mypass") } } x.report("Sha1:") { 100.times { Digest::SHA1.hexdigest("mypass") } } end user system total real BCrypt (cost = 10): 37.360000 0.020000 37.380000 ( 37.558943) BCrypt (cost = 4): 0.680000 0.000000 0.680000 ( 0.677460) Sha512: 0.000000 0.000000 0.000000 ( 0.000672) Sha1: 0.000000 0.000000 0.000000 ( 0.000454)
You can play around with the cost to get that perfect balance between performance and security.
Decided BCrypt is for you? Just install the bcrypt gem:
gem install bcrypt-ruby
Tell acts_as_authentic to use it:
acts_as_authentic do |c| c.crypto_provider = Authlogic::CryptoProviders::BCrypt end
You are good to go!
This is the :cost option for the BCrpyt library. The higher the cost the more secure it is and the longer is take the generate a hash. By default this is 10. Set this to any value >= the engine's minimum (currently 4), play around with it to get that perfect balance between security and performance.
# File lib/authlogic/crypto_providers/bcrypt.rb, line 48 def cost @cost ||= 10 end
# File lib/authlogic/crypto_providers/bcrypt.rb, line 51 def cost=(val) if val < ::BCrypt::Engine::MIN_COST raise ArgumentError.new("Authlogic's bcrypt cost cannot be set below the engine's min cost (#{::BCrypt::Engine::MIN_COST})") end @cost = val end
This method is used as a flag to tell Authlogic to "resave" the password upon a successful login, using the new cost
# File lib/authlogic/crypto_providers/bcrypt.rb, line 71 def cost_matches?(hash) hash = new_from_hash(hash) if hash.blank? false else hash.cost == cost end end
Creates a BCrypt hash for the password passed.
# File lib/authlogic/crypto_providers/bcrypt.rb, line 59 def encrypt(*tokens) ::BCrypt::Password.create(join_tokens(tokens), :cost => cost) end
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