diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 342d443..e772bb2 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -14,7 +14,6 @@ jobs:
         os:
         - windows-2019
         - windows-2022
-        - macos-11
         - macos-12
         - ubuntu-20.04
         - ubuntu-22.04
diff --git a/.github/workflows/reusable-verify.yml b/.github/workflows/reusable-verify.yml
index 6ff8011..c44663c 100644
--- a/.github/workflows/reusable-verify.yml
+++ b/.github/workflows/reusable-verify.yml
@@ -22,12 +22,6 @@ on:
       SSH_KEY_PEM:
         required: true
         description: SSH private key (PEM format)
-      SSH_KEY_PKCS8:
-        required: true
-        description: SSH private key (PKCS8 format)
-      SSH_KEY_RFC4716:
-        required: true
-        description: SSH private key (RFC4716 format)
 
 jobs:
   ssh-pem:
@@ -48,42 +42,6 @@ jobs:
     - name: git clone through SSH
       run: git clone git@github.com:step-security/ssh-key-action.git tmp
 
-  ssh-pkcs8:
-    name: Connect to github.com (PKCS8 format)
-    runs-on: ${{ inputs.os }}
-    container: ${{ inputs.docker_image }}
-    steps:
-    - name: Install packages
-      run: ${{ inputs.package_installation_command }}
-      if: ${{ inputs.package_installation_command != '' }}
-    - name: Checkout source codes
-      uses: actions/checkout@v3
-    - name: Install SSH key
-      uses: ./.
-      with:
-        key: ${{ secrets.SSH_KEY_PKCS8 }}
-        known_hosts: unnecessary
-    - name: git clone through SSH
-      run: git clone git@github.com:step-security/ssh-key-action.git tmp
-
-  ssh-rfc4716:
-    name: Connect to github.com (RFC4716 format)
-    runs-on: ${{ inputs.os }}
-    container: ${{ inputs.docker_image }}
-    steps:
-    - name: Install packages
-      run: ${{ inputs.package_installation_command }}
-      if: ${{ inputs.package_installation_command != '' }}
-    - name: Checkout source codes
-      uses: actions/checkout@v3
-    - name: Install SSH key
-      uses: ./.
-      with:
-        key: ${{ secrets.SSH_KEY_RFC4716 }}
-        known_hosts: unnecessary
-    - name: git clone through SSH
-      run: git clone git@github.com:step-security/ssh-key-action.git tmp
-
   key_if_exists_replace-key_exists:
     name: if_key_exists=replace / key exists
     runs-on: ${{ inputs.os }}
diff --git a/.github/workflows/verify-on-container-alpine.yml b/.github/workflows/verify-on-container-alpine.yml
index 8b103b1..de510e6 100644
--- a/.github/workflows/verify-on-container-alpine.yml
+++ b/.github/workflows/verify-on-container-alpine.yml
@@ -14,7 +14,6 @@ jobs:
         - ubuntu-20.04
         - ubuntu-22.04
         docker_image:
-        - alpine:3.10
         - alpine:3.11
         - alpine:3.12
         - alpine:3.13
diff --git a/.github/workflows/verify-on-container-centos.yml b/.github/workflows/verify-on-container-centos.yml
deleted file mode 100644
index ce22c93..0000000
--- a/.github/workflows/verify-on-container-centos.yml
+++ /dev/null
@@ -1,23 +0,0 @@
-# https://help.github.com/en/articles/workflow-syntax-for-github-actions
-name: Docker container (CentOS)
-
-on:
-- push
-
-jobs:
-  verify:
-    name: Verify
-    strategy:
-      fail-fast: false
-      matrix:
-        os:
-        - ubuntu-20.04
-        - ubuntu-22.04
-        docker_image:
-        - quay.io/centos/centos:stream8
-    uses: "./.github/workflows/reusable-verify.yml"
-    with:
-      os: ${{ matrix.os }}
-      docker_image: ${{ matrix.docker_image }}
-      package_installation_command: yum install -y git openssh-clients
-    secrets: inherit
diff --git a/.github/workflows/verify-on-macos.yml b/.github/workflows/verify-on-macos.yml
index ce04bc9..3833a22 100644
--- a/.github/workflows/verify-on-macos.yml
+++ b/.github/workflows/verify-on-macos.yml
@@ -11,7 +11,6 @@ jobs:
       fail-fast: false
       matrix:
         os:
-        - macos-11
         - macos-12
     uses: "./.github/workflows/reusable-verify.yml"
     with:
diff --git a/.github/workflows/verify-on-windows.yml b/.github/workflows/verify-on-windows.yml
deleted file mode 100644
index 0501a40..0000000
--- a/.github/workflows/verify-on-windows.yml
+++ /dev/null
@@ -1,19 +0,0 @@
-# https://help.github.com/en/articles/workflow-syntax-for-github-actions
-name: Windows
-
-on:
-- push
-
-jobs:
-  verify:
-    name: Verify
-    strategy:
-      fail-fast: false
-      matrix:
-        os:
-        - windows-2019
-        - windows-2022
-    uses: "./.github/workflows/reusable-verify.yml"
-    with:
-      os: ${{ matrix.os }}
-    secrets: inherit
diff --git a/README.md b/README.md
index ecba8bf..71c71aa 100644
--- a/README.md
+++ b/README.md
@@ -154,7 +154,6 @@ It is `known_hosts: unnecessary`.
 
 The scripts and documentation in this project are released under the [MIT License](LICENSE)
 
-
 [image-build]: https://github.com/step-security/ssh-key-action/workflows/Build/badge.svg?event=push&branch=v2
 [link-build]: https://github.com/step-security/ssh-key-action/actions/workflows/build.yml
 [image-verify-windows]: https://github.com/step-security/ssh-key-action/workflows/Windows/badge.svg?event=push&branch=v2
diff --git a/SECURITY.md b/SECURITY.md
index 77568b2..494cc80 100644
--- a/SECURITY.md
+++ b/SECURITY.md
@@ -2,4 +2,4 @@
 
 ## Reporting a Vulnerability
 
-Please report security vulnerabilities to security@stepsecurity.io
+Please report security vulnerabilities to [security@stepsecurity](security@stepsecurity.io)