diff --git a/Gemfile b/Gemfile
index 21a9ac1..9b04095 100644
--- a/Gemfile
+++ b/Gemfile
@@ -37,3 +37,5 @@ gem "capistrano-bundler", require: false
 gem 'capistrano-git-with-submodules', '~> 2.0'
 
 gem "jekyll-paginate"
+
+gem 'ed25519', '~> 1.2', '>= 1.2.4'
diff --git a/Gemfile.lock b/Gemfile.lock
index 4c8d95c..67409b5 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -19,6 +19,7 @@ GEM
       sshkit (~> 1.3)
     colorator (1.1.0)
     concurrent-ruby (1.1.8)
+    ed25519 (1.2.4)
     em-websocket (0.5.2)
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0.6.0)
@@ -95,6 +96,7 @@ DEPENDENCIES
   capistrano-bundler
   capistrano-git-with-submodules (~> 2.0)
   capistrano-rbenv
+  ed25519 (~> 1.2, >= 1.2.4)
   jekyll (~> 4.2.0)
   jekyll-feed (~> 0.12)
   jekyll-paginate
@@ -104,4 +106,4 @@ DEPENDENCIES
   wdm (~> 0.1.1)
 
 BUNDLED WITH
-   2.2.17
+   2.3.4