diff --git a/.rubocop.yml b/.rubocop.yml
index faa6d04..38ba3e2 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -2,3 +2,4 @@ Metrics/BlockLength:
   IgnoredMethods: ['describe', 'context']
 AllCops:
     NewCops: enable
+    TargetRubyVersion: 2.7.7
diff --git a/lib/minisign.rb b/lib/minisign.rb
index ad4503e..3e617fe 100644
--- a/lib/minisign.rb
+++ b/lib/minisign.rb
@@ -3,95 +3,5 @@
 require 'ed25519'
 require 'base64'
 require 'openssl'
-
-# `minisign` is a rubygem for verifying {https://jedisct1.github.io/minisign minisign} signatures.
-# @author Jesse Shawl
-module Minisign
-  # Parse a .minisig file's contents
-  class Signature
-    # @param str [String] The contents of the .minisig file
-    # @example
-    #   Minisign::Signature.new(File.read('test/example.txt.minisig'))
-    def initialize(str)
-      @lines = str.split("\n")
-    end
-
-    # @return [String] the key id
-    # @example
-    #   Minisign::Signature.new(File.read('test/example.txt.minisig')).key_id
-    #   #=> "E86FECED695E8E0"
-    def key_id
-      encoded_signature[2..9].bytes.map { |c| c.to_s(16) }.reverse.join.upcase
-    end
-
-    # @return [String] the trusted comment
-    # @example
-    #   Minisign::Signature.new(File.read('test/example.txt.minisig')).trusted_comment
-    #   #=> "timestamp:1653934067\tfile:example.txt\thashed"
-    def trusted_comment
-      @lines[2].split('trusted comment: ')[1]
-    end
-
-    def trusted_comment_signature
-      Base64.decode64(@lines[3])
-    end
-
-    # @return [String] the signature
-    def signature
-      encoded_signature[10..]
-    end
-
-    private
-
-    def encoded_signature
-      Base64.decode64(@lines[1])
-    end
-  end
-
-  # Parse ed25519 verify key from minisign public key
-  class PublicKey
-    # Parse the ed25519 verify key from the minisign public key
-    #
-    # @param str [String] The minisign public key
-    # @example
-    #   Minisign::PublicKey.new('RWTg6JXWzv6GDtDphRQ/x7eg0LaWBcTxPZ7i49xEeiqXVcR+r79OZRWM')
-    def initialize(str)
-      @decoded = Base64.strict_decode64(str)
-      @public_key = @decoded[10..]
-      @verify_key = Ed25519::VerifyKey.new(@public_key)
-    end
-
-    # @return [String] the key id
-    # @example
-    #   Minisign::PublicKey.new('RWTg6JXWzv6GDtDphRQ/x7eg0LaWBcTxPZ7i49xEeiqXVcR+r79OZRWM').key_id
-    #   #=> "E86FECED695E8E0"
-    def key_id
-      @decoded[2..9].bytes.map { |c| c.to_s(16) }.reverse.join.upcase
-    end
-
-    # Verify a message's signature
-    #
-    # @param sig [Minisign::Signature]
-    # @param message [String] the content that was signed
-    # @return [String] the trusted comment
-    # @raise Ed25519::VerifyError on invalid signatures
-    # @raise RuntimeError on tampered trusted comments
-    def verify(sig, message)
-      blake = OpenSSL::Digest.new('BLAKE2b512')
-      ensure_matching_key_ids(sig.key_id, key_id)
-      @verify_key.verify(sig.signature, blake.digest(message))
-      begin
-        @verify_key.verify(sig.trusted_comment_signature, sig.signature + sig.trusted_comment)
-      rescue Ed25519::VerifyError
-        raise 'Comment signature verification failed'
-      end
-      "Signature and comment signature verified\nTrusted comment: #{sig.trusted_comment}"
-    end
-
-    private
-
-    def ensure_matching_key_ids(key_id1, key_id2)
-      raise "Signature key id is #{key_id1}\nbut the key id in the public key is #{key_id2}" unless key_id1 == key_id2
-    end
-  end
-end
+require 'signature'
+require 'public_key'
diff --git a/lib/public_key.rb b/lib/public_key.rb
new file mode 100644
index 0000000..39e7355
--- /dev/null
+++ b/lib/public_key.rb
@@ -0,0 +1,50 @@
+# frozen_string_literal: true
+
+module Minisign
+  # Parse ed25519 verify key from minisign public key
+  class PublicKey
+    # Parse the ed25519 verify key from the minisign public key
+    #
+    # @param str [String] The minisign public key
+    # @example
+    #   Minisign::PublicKey.new('RWTg6JXWzv6GDtDphRQ/x7eg0LaWBcTxPZ7i49xEeiqXVcR+r79OZRWM')
+    def initialize(str)
+      @decoded = Base64.strict_decode64(str)
+      @public_key = @decoded[10..]
+      @verify_key = Ed25519::VerifyKey.new(@public_key)
+    end
+
+    # @return [String] the key id
+    # @example
+    #   Minisign::PublicKey.new('RWTg6JXWzv6GDtDphRQ/x7eg0LaWBcTxPZ7i49xEeiqXVcR+r79OZRWM').key_id
+    #   #=> "E86FECED695E8E0"
+    def key_id
+      @decoded[2..9].bytes.map { |c| c.to_s(16) }.reverse.join.upcase
+    end
+
+    # Verify a message's signature
+    #
+    # @param sig [Minisign::Signature]
+    # @param message [String] the content that was signed
+    # @return [String] the trusted comment
+    # @raise Ed25519::VerifyError on invalid signatures
+    # @raise RuntimeError on tampered trusted comments
+    def verify(sig, message)
+      blake = OpenSSL::Digest.new('BLAKE2b512')
+      ensure_matching_key_ids(sig.key_id, key_id)
+      @verify_key.verify(sig.signature, blake.digest(message))
+      begin
+        @verify_key.verify(sig.trusted_comment_signature, sig.signature + sig.trusted_comment)
+      rescue Ed25519::VerifyError
+        raise 'Comment signature verification failed'
+      end
+      "Signature and comment signature verified\nTrusted comment: #{sig.trusted_comment}"
+    end
+
+    private
+
+    def ensure_matching_key_ids(key_id1, key_id2)
+      raise "Signature key id is #{key_id1}\nbut the key id in the public key is #{key_id2}" unless key_id1 == key_id2
+    end
+  end
+end
diff --git a/lib/signature.rb b/lib/signature.rb
new file mode 100644
index 0000000..56745b4
--- /dev/null
+++ b/lib/signature.rb
@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+module Minisign
+  # Parse a .minisig file's contents
+  class Signature
+    # @param str [String] The contents of the .minisig file
+    # @example
+    #   Minisign::Signature.new(File.read('test/example.txt.minisig'))
+    def initialize(str)
+      @lines = str.split("\n")
+    end
+
+    # @return [String] the key id
+    # @example
+    #   Minisign::Signature.new(File.read('test/example.txt.minisig')).key_id
+    #   #=> "E86FECED695E8E0"
+    def key_id
+      encoded_signature[2..9].bytes.map { |c| c.to_s(16) }.reverse.join.upcase
+    end
+
+    # @return [String] the trusted comment
+    # @example
+    #   Minisign::Signature.new(File.read('test/example.txt.minisig')).trusted_comment
+    #   #=> "timestamp:1653934067\tfile:example.txt\thashed"
+    def trusted_comment
+      @lines[2].split('trusted comment: ')[1]
+    end
+
+    def trusted_comment_signature
+      Base64.decode64(@lines[3])
+    end
+
+    # @return [String] the signature
+    def signature
+      encoded_signature[10..]
+    end
+
+    private
+
+    def encoded_signature
+      Base64.decode64(@lines[1])
+    end
+  end
+end
diff --git a/minisign.gemspec b/minisign.gemspec
index 21de057..3c20870 100644
--- a/minisign.gemspec
+++ b/minisign.gemspec
@@ -12,6 +12,6 @@ Gem::Specification.new do |s|
     'https://rubygems.org/gems/minisign'
   s.license = 'MIT'
   s.add_runtime_dependency 'ed25519', '~> 1.3'
-  s.required_ruby_version = '>= 2.6.0'
+  s.required_ruby_version = '>= 2.7.7'
   s.metadata['rubygems_mfa_required'] = 'true'
 end