diff --git a/Pipfile.lock b/Pipfile.lock
index 318ed48..fc85bbb 100644
--- a/Pipfile.lock
+++ b/Pipfile.lock
@@ -28,20 +28,20 @@
         },
         "boto3": {
             "hashes": [
-                "sha256:0f4089e230d55f981d67376e48cefd41c3d58c7f694480f13288e6ff7b1fefbc",
-                "sha256:65f0d98a3786ec729ba9b5f70448895b2d1d1f27949aa7af5cb4f39da341bbc4"
+                "sha256:a5d005667b480c844ed3f814a59f199ce249d0f5669532a17d06200c0a93119c",
+                "sha256:bfcc665227bb4432a235cb4adb47719438d6472e5ccbf7f09512046c3f749670"
             ],
             "index": "pypi",
             "markers": "python_version >= '3.9'",
-            "version": "==1.42.4"
+            "version": "==1.42.14"
         },
         "botocore": {
             "hashes": [
-                "sha256:c3b091fd33809f187824b6434e518b889514ded5164cb379358367c18e8b0d7d",
-                "sha256:d4816023492b987a804f693c2d76fb751fdc8755d49933106d69e2489c4c0f98"
+                "sha256:cf5bebb580803c6cfd9886902ca24834b42ecaa808da14fb8cd35ad523c9f621",
+                "sha256:efe89adfafa00101390ec2c371d453b3359d5f9690261bc3bd70131e0d453e8e"
             ],
             "markers": "python_version >= '3.9'",
-            "version": "==1.42.4"
+            "version": "==1.42.14"
         },
         "jinja2": {
             "hashes": [
@@ -198,11 +198,11 @@
         },
         "urllib3": {
             "hashes": [
-                "sha256:c90f7a39f716c572c4e3e58509581ebd83f9b59cced005b7db7ad2d22b0db99f",
-                "sha256:cb9bcef5a4b345d5da5d145dc3e30834f58e8018828cbc724d30b4cb7d4d49f1"
+                "sha256:016f9c98bb7e98085cb2b4b17b87d2c702975664e4f060c6532e64d1c1a5e797",
+                "sha256:ec21cddfe7724fc7cb4ba4bea7aa8e2ef36f607a4bab81aa6ce42a13dc3f03dd"
             ],
             "markers": "python_version >= '3.9'",
-            "version": "==2.6.0"
+            "version": "==2.6.2"
         }
     },
     "develop": {}
diff --git a/environments/sample/main.tf b/environments/sample/main.tf
index 1adb2f3..96beae9 100644
--- a/environments/sample/main.tf
+++ b/environments/sample/main.tf
@@ -14,6 +14,11 @@ module "aws_iam" {
     arn  = module.aws_dynamodb.link_table.arn
   }
 
+  ddb_link_nonce_table = {
+    name = module.aws_dynamodb.link_nonce_table.name
+    arn  = module.aws_dynamodb.link_nonce_table.arn
+  }
+
   lambda_redirect_request = {
     name = module.aws_lambda.lambda_redirect_request.function_name
     arn  = module.aws_lambda.lambda_redirect_request.arn
@@ -40,6 +45,11 @@ module "aws_lambda" {
     arn  = module.aws_dynamodb.link_table.arn
   }
 
+  ddb_link_nonce_table = {
+    name = module.aws_dynamodb.link_nonce_table.name
+    arn  = module.aws_dynamodb.link_nonce_table.arn
+  }
+
   role_redirect_request = {
     name = module.aws_iam.role_lambda_redirect_request.name
     arn  = module.aws_iam.role_lambda_redirect_request.arn
@@ -50,9 +60,10 @@ module "aws_lambda" {
     arn  = module.aws_iam.role_lambda_admin_portal.arn
   }
 
-  link_prefix                    = "" # TODO: Change value as needed (e.g. https://example.com/dev/.... -> "dev")
-  allowed_domain                 = local.config["allowed_domain"]
-  reserved_concurrent_executions = local.config["aws"]["lambda"]["reserved_concurrent_executions"]
+  link_prefix                           = "" # TODO: Change value as needed (e.g. https://example.com/dev/.... -> "dev")
+  allowed_domain                        = local.config["allowed_domain"]
+  protected_link_request_nonce_lifetime = 300 # TODO: Change value as needed
+  reserved_concurrent_executions        = local.config["aws"]["lambda"]["reserved_concurrent_executions"]
 }
 
 module "aws_s3" {
diff --git a/lambda/admin_portal/app.py b/lambda/admin_portal/app.py
index 6d5da58..ae03de9 100644
--- a/lambda/admin_portal/app.py
+++ b/lambda/admin_portal/app.py
@@ -6,11 +6,12 @@
 from portal_page.link_create import PortalLinkCreatePage
 from portal_page.link_list import PortalListPage
 from portal_page.link_update import PortalLinkUpdatePage
-from util.logger_util import setup_logger
+from util.logger_util import setup_logger, setup_dev_logger
 from util.parse_util import parse_domain, parse_request_path
 from util.response_util import error_response
 
 logger = setup_logger("admin_portal")
+setup_dev_logger()
 
 
 @event_source(data_class=APIGatewayProxyEvent)
diff --git a/lambda/admin_portal/portal_page/link_create.py b/lambda/admin_portal/portal_page/link_create.py
index 495dfd7..2dd2841 100644
--- a/lambda/admin_portal/portal_page/link_create.py
+++ b/lambda/admin_portal/portal_page/link_create.py
@@ -37,6 +37,7 @@ def _parse_request_data(cls, domain: str, _body: str) -> Optional[DelibirdLink]:
                 tag=set(body["tag"]) if "tag" in body else None,
                 expiration_date=as_jst(datetime.fromisoformat(str(body["expiration_date"]))) if "expiration_date" in body else None,
                 expired_origin=str(body["expired_origin"]) if "expired_origin" in body else None,
+                _passphrase=str(body["passphrase"]) if "passphrase" in body else None,
                 query_omit=bool(body["query_omit"]),
                 query_whitelist=set(body["query_whitelist"]) if "query_whitelist" in body else None,
                 max_uses=int(body["max_uses"]) if "max_uses" in body else None,
@@ -84,6 +85,7 @@ def perform(cls, domain: str, event: APIGatewayProxyEvent):
                 tag=link_data.tag,
                 expiration_date=link_data.expiration_date,
                 expired_origin=link_data.expired_origin,
+                passphrase=link_data._passphrase,  # allow read private field
                 query_omit=link_data.query_omit,
                 query_whitelist=link_data.query_whitelist,
                 max_uses=link_data.max_uses
diff --git a/lambda/admin_portal/portal_page/link_update.py b/lambda/admin_portal/portal_page/link_update.py
index 03a3cb9..8556c72 100644
--- a/lambda/admin_portal/portal_page/link_update.py
+++ b/lambda/admin_portal/portal_page/link_update.py
@@ -36,6 +36,7 @@ def _parse_request_data(cls, domain: str, _body: str) -> Optional[DelibirdLink]:
                 tag=set(body["tag"]) if "tag" in body else None,
                 expiration_date=as_jst(datetime.fromisoformat(str(body["expiration_date"]))) if "expiration_date" in body else None,
                 expired_origin=str(body["expired_origin"]) if "expired_origin" in body else None,
+                _passphrase=str(body["passphrase"]) if "passphrase" in body else None,
                 query_omit=bool(body["query_omit"]),
                 query_whitelist=set(body["query_whitelist"]) if "query_whitelist" in body else None,
                 max_uses=int(body["max_uses"]) if "max_uses" in body else None,
@@ -77,6 +78,7 @@ def perform(cls, domain: str, event: APIGatewayProxyEvent):
                 DelibirdLinkTableModel.tag.set(link_data.tag),
                 DelibirdLinkTableModel.expiration_date.set(link_data.expiration_date),
                 DelibirdLinkTableModel.expired_origin.set(link_data.expired_origin),
+                DelibirdLinkTableModel.passphrase.set(link_data._passphrase),  # allow read private field
                 DelibirdLinkTableModel.query_omit.set(link_data.query_omit),
                 DelibirdLinkTableModel.query_whitelist.set(link_data.query_whitelist),
                 DelibirdLinkTableModel.max_uses.set(link_data.max_uses),
diff --git a/lambda/admin_portal/static/links.html b/lambda/admin_portal/static/links.html
index 23af538..6d008d0 100644
--- a/lambda/admin_portal/static/links.html
+++ b/lambda/admin_portal/static/links.html
@@ -7,7 +7,7 @@
         <!-- Bootstrap CSS -->
         <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0/dist/css/bootstrap.min.css" integrity="sha384-9ndCyUaIbzAi2FUVXJi0CjmCapSmO7SnpJef0486qhLnuZ2cdeRhO02iuK6FUUVM" crossorigin="anonymous">
         <!-- Bootstrap Icons -->
-        <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap-icons@1.11.3/font/bootstrap-icons.min.css" integrity="sha384-XGjxtQfXaH2tnPFa9x+ruJTuLE3Aa6LhHSWRr1XeTyhezb4abCG4ccI5AkVDxqC+" crossorigin="anonymous">
+        <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap-icons@1.13.1/font/bootstrap-icons.min.css" integrity="sha384-CK2SzKma4jA5H/MXDUU7i1TqZlCFaD4T01vtyDFvPlD97JQyS+IsSh1nI2EFbpyk" crossorigin="anonymous">
         <link rel="stylesheet" href="https://static.kazutech.jp/l/css/admin-portal.css">
     </head>
     <body class="bg-light">
@@ -110,6 +110,11 @@ <h5 class="mb-0"><i class="bi bi-table"></i> Link Details</h5>
                                            data-bs-html="true"
                                            title="{{ link.tag|join(', ') }}"></i>
                                         {% endif %}
+                                        {% if link.is_protected() %}
+                                        <i class="bi bi-lock-fill ms-1"
+                                           data-bs-toggle="tooltip"
+                                           data-bs-placement="top"></i>
+                                        {% endif %}
                                     </td>
 
                                     <!-- Origin -->
@@ -201,6 +206,7 @@ <h5 class="mb-0"><i class="bi bi-table"></i> Link Details</h5>
                                                 data-max-uses="{{ link.max_uses or '' }}"
                                                 data-expiration="{{ link.expiration_date.strftime('%Y-%m-%dT%H:%M') if link.expiration_date else '' }}"
                                                 data-expired-origin="{{ link.expired_origin or '' }}"
+                                                data-passphrase="{{ link._passphrase or '' }}"
                                                 data-query-omit="{{ 'true' if link.query_omit else 'false' }}"
                                                 data-query-whitelist="{{ link.query_whitelist|join(',') if link.query_whitelist else '' }}"
                                                 data-memo="{{ link.memo or '' }}"
@@ -241,8 +247,8 @@ <h5 class="modal-title" id="createLinkModalLabel">
                                     <div class="col-md-6 mb-3">
                                         <label for="linkSlug" class="form-label">Slug <span class="text-danger">*</span></label>
                                         <input type="text" class="form-control" id="linkSlug" name="link_slug" required
-                                               pattern="[a-zA-Z0-9_\-]+" title="英数字、ハイフン、アンダースコアのみ使用可能">
-                                        <div class="form-text">英数字、ハイフン、アンダースコアのみ使用可能</div>
+                                               pattern="[a-zA-Z0-9_\-/]+" title="英数字、ハイフン、アンダースコア、スラッシュのみ">
+                                        <div class="form-text">英数字、ハイフン、アンダースコア、スラッシュのみ</div>
                                     </div>
 
                                     <!-- HTTP Status -->
@@ -320,6 +326,19 @@ <h5 class="modal-title" id="createLinkModalLabel">
                                     <div class="form-text">期限切れ時のリダイレクト先URL（オプション）</div>
                                 </div>
 
+                                <!-- Passphrase -->
+                                <div class="mb-3">
+                                    <label for="passphrase" class="form-label">Passphrase</label>
+                                    <div class="password-field-wrapper">
+                                        <input type="password" class="form-control password-input-field" id="passphrase" name="passphrase"
+                                               placeholder="パスワードを入力" autocomplete="off">
+                                        <button type="button" class="password-toggle-btn" id="togglePassphrase" aria-label="パスワードの表示切替">
+                                            <i class="bi bi-eye" aria-hidden="true"></i>
+                                        </button>
+                                    </div>
+                                    <div class="form-text">リンクにアクセスするためのパスワード（オプション）</div>
+                                </div>
+
                                 <!-- Memo -->
                                 <div class="mb-3">
                                     <label for="memo" class="form-label">Memo</label>
@@ -444,6 +463,19 @@ <h5 class="modal-title" id="editLinkModalLabel">
                                     <div class="form-text">期限切れ時のリダイレクト先URL（オプション）</div>
                                 </div>
 
+                                <!-- Passphrase -->
+                                <div class="mb-3">
+                                    <label for="editPassphrase" class="form-label">Passphrase</label>
+                                    <div class="password-field-wrapper">
+                                        <input type="password" class="form-control password-input-field" id="editPassphrase" name="passphrase"
+                                               placeholder="パスワードを入力" autocomplete="off">
+                                        <button type="button" class="password-toggle-btn" id="toggleEditPassphrase" aria-label="パスワードの表示切替">
+                                            <i class="bi bi-eye" aria-hidden="true"></i>
+                                        </button>
+                                    </div>
+                                    <div class="form-text">リンクにアクセスするためのパスワード（オプション）</div>
+                                </div>
+
                                 <!-- Memo -->
                                 <div class="mb-3">
                                     <label for="editMemo" class="form-label">Memo</label>
@@ -483,7 +515,22 @@ <h5 class="modal-title" id="editLinkModalLabel">
         <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0/dist/js/bootstrap.bundle.min.js" integrity="sha384-geWF76RCwLtnZ8qwWowPQNguL3RmwHVBC9FhGdlKrxdiJJigb/j/68SIy3Te4Bkz" crossorigin="anonymous"></script>
 
         <!-- Custom JS -->
-        <script{% if script_nonce %} nonce="{{ script_nonce }}"{% endif %}>
+        <script {%- if script_nonce %} nonce="{{ script_nonce }}"{%- endif %}>
+            // パスフレーズのバリデーション
+            function validatePassphrase(passphrase) {
+                if (!passphrase || passphrase === '') {
+                    return { valid: true };
+                }
+
+                // 許可される文字: 英数字と -_/*+.!#$%&~@=^
+                const passphrasePattern = /^[a-zA-Z0-9\-_/*+.!#$%&~@=^]+$/;
+                if (!passphrasePattern.test(passphrase)) {
+                    return { valid: false, message: 'パスフレーズに使用できない文字が含まれています。\n使用可能な文字: 英数字、-_/*+.!#$%&~@=^' };
+                }
+
+                return { valid: true };
+            }
+
             // Query Omit チェックボックスの制御
             document.addEventListener('DOMContentLoaded', function() {
                 // Bootstrap ツールチップの初期化
@@ -492,6 +539,32 @@ <h5 class="modal-title" id="editLinkModalLabel">
                     return new bootstrap.Tooltip(tooltipTriggerEl);
                 });
 
+                // パスワード表示トグル機能（作成モーダル）
+                const togglePassphraseBtn = document.getElementById('togglePassphrase');
+                const passphraseInput = document.getElementById('passphrase');
+                if (togglePassphraseBtn && passphraseInput) {
+                    togglePassphraseBtn.addEventListener('click', function() {
+                        const isPassword = passphraseInput.type === 'password';
+                        passphraseInput.type = isPassword ? 'text' : 'password';
+                        const icon = togglePassphraseBtn.querySelector('i');
+                        icon.classList.toggle('bi-eye');
+                        icon.classList.toggle('bi-eye-slash');
+                    });
+                }
+
+                // パスワード表示トグル機能（編集モーダル）
+                const toggleEditPassphraseBtn = document.getElementById('toggleEditPassphrase');
+                const editPassphraseInput = document.getElementById('editPassphrase');
+                if (toggleEditPassphraseBtn && editPassphraseInput) {
+                    toggleEditPassphraseBtn.addEventListener('click', function() {
+                        const isPassword = editPassphraseInput.type === 'password';
+                        editPassphraseInput.type = isPassword ? 'text' : 'password';
+                        const icon = toggleEditPassphraseBtn.querySelector('i');
+                        icon.classList.toggle('bi-eye');
+                        icon.classList.toggle('bi-eye-slash');
+                    });
+                }
+
                 const queryOmitCheckbox = document.getElementById('queryOmit');
                 const queryWhitelistContainer = document.getElementById('queryWhitelistContainer');
                 const queryWhitelistInput = document.getElementById('queryWhitelist');
@@ -522,7 +595,7 @@ <h5 class="modal-title" id="editLinkModalLabel">
                     e.stopPropagation();
 
                     const slugInput = document.getElementById('linkSlug');
-                    const slugPattern = /^[a-zA-Z0-9_-]+$/;
+                    const slugPattern = /^[a-zA-Z0-9_\-/]+$/;
 
                     if (!slugInput.value) {
                         alert('Slugを入力してください。');
@@ -530,7 +603,7 @@ <h5 class="modal-title" id="editLinkModalLabel">
                     }
 
                     if (!slugPattern.test(slugInput.value)) {
-                        alert('Slugは英数字、ハイフン、アンダースコアのみ使用可能です。');
+                        alert('Slugは英数字、ハイフン、アンダースコア、スラッシュのみ使用可能です。');
                         return;
                     }
 
@@ -540,6 +613,14 @@ <h5 class="modal-title" id="editLinkModalLabel">
                         return;
                     }
 
+                    // パスフレーズのバリデーション
+                    const passphrase = document.getElementById('passphrase').value;
+                    const passphraseValidation = validatePassphrase(passphrase);
+                    if (!passphraseValidation.valid) {
+                        alert(passphraseValidation.message);
+                        return;
+                    }
+
                     // JSONデータを作成
                     const data = {
                         link_slug: document.getElementById('linkSlug').value,
@@ -566,6 +647,10 @@ <h5 class="modal-title" id="editLinkModalLabel">
                         data.expired_origin = expiredOrigin;
                     }
 
+                    if (passphrase) {
+                        data.passphrase = passphrase;
+                    }
+
                     const memo = document.getElementById('memo').value;
                     if (memo) {
                         data.memo = memo;
@@ -616,6 +701,18 @@ <h5 class="modal-title" id="editLinkModalLabel">
                 createLinkModal.addEventListener('hidden.bs.modal', function() {
                     createLinkForm.reset();
                     updateQueryWhitelistState();
+
+                    // パスワード入力欄を非表示状態にリセット
+                    if (passphraseInput) {
+                        passphraseInput.type = 'password';
+                    }
+                    if (togglePassphraseBtn) {
+                        const icon = togglePassphraseBtn.querySelector('i');
+                        if (icon) {
+                            icon.classList.remove('bi-eye-slash');
+                            icon.classList.add('bi-eye');
+                        }
+                    }
                 });
 
                 // === 編集機能 ===
@@ -649,6 +746,7 @@ <h5 class="modal-title" id="editLinkModalLabel">
                         const maxUses = this.getAttribute('data-max-uses');
                         const expiration = this.getAttribute('data-expiration');
                         const expiredOrigin = this.getAttribute('data-expired-origin');
+                        const passphrase = this.getAttribute('data-passphrase');
                         const queryOmit = this.getAttribute('data-query-omit') === 'true';
                         const queryWhitelist = this.getAttribute('data-query-whitelist');
                         const memo = this.getAttribute('data-memo');
@@ -667,6 +765,17 @@ <h5 class="modal-title" id="editLinkModalLabel">
                         document.getElementById('editMemo').value = memo;
                         document.getElementById('editTag').value = tag;
 
+                        // パスワードを表示（既存のパスワードを確認できるように）
+                        document.getElementById('editPassphrase').value = passphrase;
+                        document.getElementById('editPassphrase').type = 'password';
+                        if (toggleEditPassphraseBtn) {
+                            const icon = toggleEditPassphraseBtn.querySelector('i');
+                            if (icon) {
+                                icon.classList.remove('bi-eye-slash');
+                                icon.classList.add('bi-eye');
+                            }
+                        }
+
                         // Query Whitelist の状態を更新
                         updateEditQueryWhitelistState();
                     });
@@ -686,6 +795,14 @@ <h5 class="modal-title" id="editLinkModalLabel">
                         return;
                     }
 
+                    // パスフレーズのバリデーション
+                    const editPassphrase = document.getElementById('editPassphrase').value;
+                    const passphraseValidation = validatePassphrase(editPassphrase);
+                    if (!passphraseValidation.valid) {
+                        alert(passphraseValidation.message);
+                        return;
+                    }
+
                     // JSONデータを作成
                     const data = {
                         domain: '{{ domain }}',
@@ -712,6 +829,10 @@ <h5 class="modal-title" id="editLinkModalLabel">
                         data.expired_origin = expiredOrigin;
                     }
 
+                    if (editPassphrase) {
+                        data.passphrase = editPassphrase;
+                    }
+
                     const memo = document.getElementById('editMemo').value;
                     if (memo) {
                         data.memo = memo;
@@ -760,6 +881,18 @@ <h5 class="modal-title" id="editLinkModalLabel">
                 editLinkModal.addEventListener('hidden.bs.modal', function() {
                     editLinkForm.reset();
                     updateEditQueryWhitelistState();
+
+                    // パスワード入力欄を非表示状態にリセット
+                    if (editPassphraseInput) {
+                        editPassphraseInput.type = 'password';
+                    }
+                    if (toggleEditPassphraseBtn) {
+                        const icon = toggleEditPassphraseBtn.querySelector('i');
+                        if (icon) {
+                            icon.classList.remove('bi-eye-slash');
+                            icon.classList.add('bi-eye');
+                        }
+                    }
                 });
             });
         </script>
diff --git a/lambda/layers/common/python/ddb/models/delibird_link.py b/lambda/layers/common/python/ddb/models/delibird_link.py
index 0c2cc41..fcebed6 100644
--- a/lambda/layers/common/python/ddb/models/delibird_link.py
+++ b/lambda/layers/common/python/ddb/models/delibird_link.py
@@ -1,6 +1,9 @@
+import hashlib
+import hmac
 import json
 import logging
 import os
+import re
 from dataclasses import dataclass
 from datetime import datetime
 from enum import Enum, auto
@@ -18,6 +21,10 @@
 from util.logger_util import setup_logger
 
 _REGION = os.environ["AWS_REGION"]
+_MAX_SLUG_LENGTH = 255
+_SLUG_PATTERN = re.compile(r'^[a-zA-Z0-9\-_]+(?:/[a-zA-Z0-9\-_]+)*$', re.ASCII)
+_MAX_PASSPHRASE_LENGTH = 255
+_PASSPHRASE_PATTERN = re.compile(r'^[A-Za-z0-9\-_/*+.!#$%&~@=^]+$', re.ASCII)
 
 logger = setup_logger("delibird.link_table", logging.INFO)
 
@@ -50,16 +57,40 @@ class DelibirdLink:
     expiration_date: Optional[datetime] = None
     expired_origin: Optional[str] = None
 
+    _passphrase: Optional[str] = None
+
     query_omit: bool = False
     query_whitelist: set[str] = None
 
     max_uses: Optional[int] = None
 
+    @staticmethod
+    def _validation(link: "DelibirdLink") -> None:
+        # domain
+        if not link.domain:
+            raise ValueError("Domain is required.")
+        # slug
+        if (not (slug := link.link_slug)) or (len(slug) > _MAX_SLUG_LENGTH) or (not _SLUG_PATTERN.fullmatch(slug)):
+            raise ValueError(f"Invalid slug: {slug}")
+        # origin
+        if not link.link_origin:
+            raise ValueError("Origin is required.")
+        # status
+        if not link.status.is_redirection:
+            raise ValueError(f"Status code {link.status} is not a redirection status.")
+        # passphrase
+        if link._passphrase is not None:
+            if len(link._passphrase) == 0:
+                link._passphrase = None
+            elif (len(link._passphrase) > _MAX_PASSPHRASE_LENGTH) or (not _PASSPHRASE_PATTERN.fullmatch(link._passphrase)):
+                raise ValueError("Invalid passphrase.")
+
     def __post_init__(self):
         if self.query_whitelist is None:
             self.query_whitelist = set()
         if self.tag is None:
             self.tag = set()
+        DelibirdLink._validation(self)
 
     def check_active(self) -> tuple[bool, Optional[DelibirdLinkInactiveReason]]:
         if self.disabled:
@@ -90,6 +121,17 @@ def increment_uses(self) -> bool:
         self.uses += 1
         return True
 
+    def is_protected(self) -> bool:
+        return (self._passphrase is not None) and (not self._passphrase.isspace())
+
+    def validate_challenge(self, nonce: str, challenge: str) -> bool:
+        if not self.is_protected():
+            raise ValueError("Link is not protected.")
+        if not nonce:
+            raise ValueError("Nonce is required.")
+        expected = hashlib.sha256(f"{self._passphrase}#{nonce}".encode()).hexdigest()
+        return hmac.compare_digest(challenge, expected)
+
     @staticmethod
     def from_model(model: "DelibirdLinkTableModel") -> "DelibirdLink":
         return DelibirdLink(
@@ -104,6 +146,7 @@ def from_model(model: "DelibirdLinkTableModel") -> "DelibirdLink":
             tag=set(model.tag) if model.tag is not None else None,
             expiration_date=as_jst(model.expiration_date) if model.expiration_date is not None else None,
             expired_origin=model.expired_origin,
+            _passphrase=model.passphrase,
             query_omit=model.query_omit,
             query_whitelist=model.query_whitelist,
             max_uses=int(model.max_uses) if model.max_uses is not None else None
@@ -128,6 +171,7 @@ class Meta:
 
     expiration_date = DateTimeAttribute(null=True)
     expired_origin = UnicodeAttribute(null=True)
+    passphrase = UnicodeAttribute(null=True)
     query_omit = BooleanAttribute(null=False, default=True)
     query_whitelist = UnicodeSetAttribute(null=True)
     max_uses = NumberAttribute(null=True)
diff --git a/lambda/layers/common/python/util/logger_util.py b/lambda/layers/common/python/util/logger_util.py
index be594b5..3a97097 100644
--- a/lambda/layers/common/python/util/logger_util.py
+++ b/lambda/layers/common/python/util/logger_util.py
@@ -1,4 +1,5 @@
 import logging
+import os
 import sys
 
 _FORMAT = '%(levelname)s %(asctime)s [%(name)s - %(funcName)s] %(message)s'
@@ -32,3 +33,11 @@ def setup_logger(name: str, level: int = logging.DEBUG):
     logger.addHandler(_ERROR_HANDLER)
     # logger.addHandler(_LOG_FILE_HANDLER)
     return logger
+
+
+def setup_dev_logger():
+    if os.environ.get("DELIBIRD_ENV") != "dev":
+        return
+    log_pynamodb = logging.getLogger("pynamodb")
+    log_pynamodb.setLevel(logging.DEBUG)
+    log_pynamodb.addHandler(_HANDLER)
diff --git a/lambda/layers/common/python/util/parse_util.py b/lambda/layers/common/python/util/parse_util.py
index 7b3b7e2..56764ce 100644
--- a/lambda/layers/common/python/util/parse_util.py
+++ b/lambda/layers/common/python/util/parse_util.py
@@ -1,4 +1,5 @@
 import os
+from typing import Optional
 from urllib.parse import quote
 from urllib.parse import urlparse
 
@@ -29,3 +30,17 @@ def parse_domain(domain: str) -> str:
     if (not domain) or (domain not in _ALLOWED_DOMAIN):
         raise ValueError(f"Invalid or missing domain: {domain}, allowed: {_ALLOWED_DOMAIN}")
     return domain
+
+
+def parse_query(query_data: dict[str, list[str]], key: str, *, allow_notfound: bool = False, expected_single_value: bool = True) \
+        -> Optional[str | list[str]]:
+    if key not in query_data:
+        if allow_notfound:
+            return None
+        raise ValueError(f"Invalid query key: {key}")
+
+    v = query_data[key]
+    if expected_single_value and len(v) != 1:
+        raise ValueError(f"Invalid query value: {v}")
+
+    return v if (not expected_single_value) else v[0]
diff --git a/lambda/layers/common/python/util/response_util.py b/lambda/layers/common/python/util/response_util.py
index 7463c40..0396243 100644
--- a/lambda/layers/common/python/util/response_util.py
+++ b/lambda/layers/common/python/util/response_util.py
@@ -24,7 +24,7 @@ def _load_error_html(status: HTTPStatus) -> tuple[Optional[str], bool]:
     return html_content, html_content is not None
 
 
-def _build_csp_header(*, use_css: bool = False, use_bootstrap: bool = False, use_self_api: bool = False,
+def _build_csp_header(*, use_css: bool = False, use_bootstrap: bool = False, use_bootstrap_icons: bool = False, use_self_api: bool = False,
                       style_nonce: str = None, script_nonce: str = None) -> str:
     script_origin = [
         "https://cdn.jsdelivr.net/npm/bootstrap@5.3.0/" if use_bootstrap else None,
@@ -33,14 +33,14 @@ def _build_csp_header(*, use_css: bool = False, use_bootstrap: bool = False, use
     style_origin = [
         "https://static.kazutech.jp/l/css/" if use_css else None,
         "https://cdn.jsdelivr.net/npm/bootstrap@5.3.0/" if use_bootstrap else None,
-        "https://cdn.jsdelivr.net/npm/bootstrap-icons@1.11.3/" if use_bootstrap else None,
+        "https://cdn.jsdelivr.net/npm/bootstrap-icons@1.13.1/" if (use_bootstrap_icons or use_bootstrap) else None,
         f"'nonce-{style_nonce}'" if style_nonce else None
     ]
     img_origin = [
-        "data:" if use_bootstrap else None,
+        "data:" if (use_bootstrap_icons or use_bootstrap) else None,
     ]
     font_origin = [
-        "https://cdn.jsdelivr.net/npm/bootstrap-icons@1.11.3/" if use_bootstrap else None
+        "https://cdn.jsdelivr.net/npm/bootstrap-icons@1.13.1/" if (use_bootstrap_icons or use_bootstrap) else None
     ]
     connect_origin = [
         "'self'" if use_self_api else None,
@@ -68,12 +68,12 @@ def _build_csp_header(*, use_css: bool = False, use_bootstrap: bool = False, use
 
 
 def _generate_response_headers(content_type: str = None, *,
-                               use_css: bool = False, use_bootstrap: bool = False, use_self_api: bool = False,
+                               use_css: bool = False, use_bootstrap: bool = False, use_bootstrap_icons: bool = False, use_self_api: bool = False,
                                style_nonce: str = None, script_nonce: str = None) -> dict[str, str]:
     headers = {
         "Content-Type": content_type or "application/json;charset=utf-8",
         "Content-Security-Policy": _build_csp_header(
-            use_css=use_css, use_bootstrap=use_bootstrap, use_self_api=use_self_api,
+            use_css=use_css, use_bootstrap=use_bootstrap, use_bootstrap_icons=use_bootstrap_icons, use_self_api=use_self_api,
             style_nonce=style_nonce, script_nonce=script_nonce),
         "Cache-Control": "private, no-cache, no-store, max-age=0, must-revalidate",
         "Pragma": "no-cache",
@@ -110,13 +110,13 @@ def error_response(status: HTTPStatus, force_json: bool = False):
 
 
 def success_response(status: HTTPStatus, body: str | dict, content_type: str = None, *,
-                     use_css: bool = False, use_bootstrap: bool = False, use_self_api: bool = False,
+                     use_css: bool = False, use_bootstrap: bool = False, use_bootstrap_icons: bool = False, use_self_api: bool = False,
                      style_nonce: str = None, script_nonce: str = None):
     return {
         "statusCode": status.value,
         "headers": _generate_response_headers(
             content_type,
-            use_css=use_css, use_bootstrap=use_bootstrap, use_self_api=use_self_api,
+            use_css=use_css, use_bootstrap=use_bootstrap, use_bootstrap_icons=use_bootstrap_icons, use_self_api=use_self_api,
             style_nonce=style_nonce, script_nonce=script_nonce),
         "body": body if isinstance(body, str) else json.dumps(body),
     }
diff --git a/lambda/redirect_request/app.py b/lambda/redirect_request/app.py
index a77ae4b..c92e896 100644
--- a/lambda/redirect_request/app.py
+++ b/lambda/redirect_request/app.py
@@ -4,12 +4,15 @@
 from aws_lambda_powertools.utilities.typing import LambdaContext
 
 from ddb.models.delibird_link import DelibirdLinkTableModel, DelibirdLinkInactiveStatus
+from models.delibird_nonce import DelibirdNonceTableModel
+from protected_util import protected_response, NONCE_QUERY_KEY, CHALLENGE_QUERY_KEY
 from query import queried_origin
-from util.logger_util import setup_logger
-from util.parse_util import parse_request_path, parse_origin, parse_domain
+from util.logger_util import setup_logger, setup_dev_logger
+from util.parse_util import parse_request_path, parse_origin, parse_domain, parse_query
 from util.response_util import redirect_response, error_response
 
 logger = setup_logger("redirect_request")
+setup_dev_logger()
 
 
 @event_source(data_class=APIGatewayProxyEvent)
@@ -78,6 +81,52 @@ def lambda_handler(event: APIGatewayProxyEvent, context: LambdaContext):
         logger.error(f"Link(domain: {domain}, slug: {request_path}) has invalid status code: {link.status}")
         return error_response(HTTPStatus.INTERNAL_SERVER_ERROR)
 
+    # リンクがパスフレーズ付きの場合
+    if link.is_protected():
+        ## nonceかchallengeがなかったら、未認証として認証ページを表示する。
+        if (NONCE_QUERY_KEY not in event.resolved_query_string_parameters) and (CHALLENGE_QUERY_KEY not in event.resolved_query_string_parameters):
+            logger.info(f"Link(domain: {domain}, slug: {request_path}) requires challenge.")
+            try:
+                return protected_response(domain, request_path)
+            except Exception:
+                logger.exception(f"Failed to generate protected response for domain: {domain}, slug: {request_path}")
+                return error_response(HTTPStatus.INTERNAL_SERVER_ERROR)
+        try:
+            ## (nonceとchallengeがあったら、) まずnonceを取り出してDBと突合(存在確認・期限内・未使用・nonceの対象リクエストか)
+            nonce: str = parse_query(event.resolved_query_string_parameters, NONCE_QUERY_KEY, expected_single_value=True)
+            nonce_model = DelibirdNonceTableModel.get(nonce)
+            if not nonce_model.is_active():
+                # nonceが使用済 or 期限切れ
+                return protected_response(domain, request_path, "認証に失敗しました。もう一度お試しください。")
+            if nonce_model.domain != domain or nonce_model.slug != request_path:
+                return protected_response(domain, request_path, "認証に失敗しました。もう一度お試しください。")
+
+            ## 問題ないnonceの場合、challengeの確認
+            challenge = parse_query(event.resolved_query_string_parameters, CHALLENGE_QUERY_KEY, expected_single_value=True)
+            if not link.validate_challenge(nonce, challenge):
+                logger.info(f"Invalid challenge for domain: {domain}, slug: {request_path}")
+                nonce_model.mark_used()  # not successでもok
+                return protected_response(domain, request_path, "パスワードが正しくありません。")
+
+            # チャレンジ成功 -> nonce消込
+            try:
+                nonce_use_success, nonce_used_at = nonce_model.mark_used()
+            except Exception:
+                logger.exception(f"Failed to mark nonce as used for domain: {domain}, slug: {request_path}")
+                return error_response(HTTPStatus.INTERNAL_SERVER_ERROR)
+            if not nonce_use_success:
+                # nonceがぎりぎり期限切れになった場合 or 競合リクエストで使用された場合
+                logger.info(f"Failed to mark nonce as used for domain: {domain}, slug: {request_path}")
+                return protected_response(domain, request_path, "認証に失敗しました。もう一度お試しください。")
+
+        except DelibirdNonceTableModel.DoesNotExist:
+            # nonceがDB上に存在しない
+            logger.info(f"Invalid nonce for domain: {domain}, slug: {request_path}")
+            return protected_response(domain, request_path, "認証に失敗しました。もう一度お試しください。")
+        except Exception:
+            logger.exception(f"Failed to parse challenge for domain: {domain}, slug: {request_path}")
+            return error_response(HTTPStatus.INTERNAL_SERVER_ERROR)
+
     # リダイレクト先URLの決定
     origin_candidate = interrupt_origin or link.link_origin
     try:
@@ -92,7 +141,8 @@ def lambda_handler(event: APIGatewayProxyEvent, context: LambdaContext):
     if not link.query_omit:
         logger.info(f"Link(domain: {domain}, slug: {request_path}) has disabled query omission. Appending query parameters.")
         try:
-            origin = queried_origin(origin, event.resolved_query_string_parameters, link.query_whitelist)
+            origin = queried_origin(origin, event.resolved_query_string_parameters, link.query_whitelist,
+                                    {NONCE_QUERY_KEY, CHALLENGE_QUERY_KEY} if link.is_protected() else set())
         except ValueError:
             logger.exception(f"Invalid query parameters for domain: {domain}, slug: {request_path}, URL: {origin}")
             return error_response(HTTPStatus.BAD_REQUEST)
diff --git a/lambda/redirect_request/models/__init__.py b/lambda/redirect_request/models/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/lambda/redirect_request/models/delibird_nonce.py b/lambda/redirect_request/models/delibird_nonce.py
new file mode 100644
index 0000000..267b21c
--- /dev/null
+++ b/lambda/redirect_request/models/delibird_nonce.py
@@ -0,0 +1,54 @@
+import os
+from datetime import datetime
+from typing import Optional
+
+from pynamodb.attributes import UnicodeAttribute, NumberAttribute
+from pynamodb.constants import NULL
+from pynamodb.exceptions import UpdateError
+from pynamodb.expressions.operand import Path
+from pynamodb.models import Model
+
+from ddb.datetime_attribute import DateTimeAttribute
+from util.date_util import get_jst_datetime_now
+
+_REGION = os.environ["AWS_REGION"]
+
+
+class DelibirdNonceTableModel(Model):
+    class Meta:
+        table_name = os.environ["NONCE_TABLE_NAME"]
+        region = _REGION
+
+    nonce = UnicodeAttribute(hash_key=True)
+    expired_timestamp = NumberAttribute(null=False)
+
+    domain = UnicodeAttribute(null=False)
+    slug = UnicodeAttribute(null=False)
+    used_at = DateTimeAttribute(null=True, default=None)
+
+    def is_active(self) -> bool:
+        if self.used_at is not None:
+            # 使用済み
+            return False
+        if self.expired_timestamp <= get_jst_datetime_now().timestamp():
+            # 期限切れ
+            return False
+        return True
+
+    def mark_used(self) -> tuple[bool, Optional[datetime]]:
+        if not self.is_active():
+            # usedな状態でmark_usedされていないか、呼び出し時点で期限切れしていないか
+            return False, None
+
+        now = get_jst_datetime_now()
+        try:
+            self.update(
+                actions=[DelibirdNonceTableModel.used_at.set(now)],
+                condition=(DelibirdNonceTableModel.used_at.does_not_exist()) |
+                          (Path(DelibirdNonceTableModel.used_at).is_type(NULL))
+            )
+        except UpdateError as e:
+            if e.cause_response_code == "ConditionalCheckFailedException":
+                return False, None
+            raise e
+        return True, now
diff --git a/lambda/redirect_request/protected_util.py b/lambda/redirect_request/protected_util.py
new file mode 100644
index 0000000..ecc4726
--- /dev/null
+++ b/lambda/redirect_request/protected_util.py
@@ -0,0 +1,44 @@
+import os
+from datetime import timedelta
+from http import HTTPStatus
+
+from models.delibird_nonce import DelibirdNonceTableModel
+from util.date_util import get_jst_datetime_now
+from util.nonce_util import create_nonce
+from util.response_util import success_response
+from util.static_resource_util import load_function_html
+
+NONCE_QUERY_KEY = "n"
+CHALLENGE_QUERY_KEY = "c"
+
+_NONCE_LIFETIME_SECONDS = int(os.environ["NONCE_LIFETIME_SECONDS"])
+
+
+def protected_response(domain: str, slug: str, error_message: str = ""):
+    script_nonce = create_nonce()
+    request_nonce = _create_protected_request_nonce(domain, slug)
+
+    html_content = load_function_html("static/protected.html", {
+        "default_error_message": error_message,
+
+        "challenge_query_key": CHALLENGE_QUERY_KEY,
+        "nonce_query_key": NONCE_QUERY_KEY,
+        "script_nonce": script_nonce,
+        "request_nonce": request_nonce
+    })
+
+    return success_response(HTTPStatus.UNAUTHORIZED, html_content,
+                            content_type='text/html;charset=utf-8', use_css=True, use_bootstrap_icons=True,
+                            script_nonce=script_nonce)
+
+
+def _create_protected_request_nonce(domain: str, slug: str) -> str:
+    nonce = create_nonce()
+
+    model = DelibirdNonceTableModel(nonce)
+    model.domain = domain
+    model.slug = slug
+    model.expired_timestamp = int((get_jst_datetime_now() + timedelta(seconds=_NONCE_LIFETIME_SECONDS)).timestamp())
+    model.save(condition=DelibirdNonceTableModel.nonce.does_not_exist())
+
+    return nonce
diff --git a/lambda/redirect_request/query.py b/lambda/redirect_request/query.py
index 37e1344..b609164 100644
--- a/lambda/redirect_request/query.py
+++ b/lambda/redirect_request/query.py
@@ -7,7 +7,7 @@
 _MAX_TOTAL_QUERY_PARAMS = int(os.environ["MAX_TOTAL_QUERY_PARAMS"])
 
 
-def queried_origin(origin: str, data: dict[str, list[str]], query_whitelist: set[str]) -> str:
+def queried_origin(origin: str, data: dict[str, list[str]], query_whitelist: set[str], query_blacklist: set[str]) -> str:
     """クエリパラメータを付与したURLを返す"""
     parsed_url = urlparse(origin)
     existing_query_pairs = [(k, v) for k, v in parse_qsl(parsed_url.query, strict_parsing=True)]
@@ -32,6 +32,10 @@ def queried_origin(origin: str, data: dict[str, list[str]], query_whitelist: set
         # ホワイトリストフィルタリング
         query_pairs = [(k, v) for k, v in query_pairs if k in query_whitelist]
 
+    if len(query_blacklist) > 0:
+        # ブラックリストフィルタリング
+        query_pairs = [(k, v) for k, v in query_pairs if k not in query_blacklist]
+
     query_string = urlencode(query_pairs, doseq=False)
     return urlunparse((
         parsed_url.scheme,
diff --git a/lambda/redirect_request/static/protected.html b/lambda/redirect_request/static/protected.html
new file mode 100644
index 0000000..a26af32
--- /dev/null
+++ b/lambda/redirect_request/static/protected.html
@@ -0,0 +1,121 @@
+<!DOCTYPE html>
+<html lang="ja">
+    <head>
+        <meta charset="UTF-8">
+        <meta name="viewport" content="width=device-width, initial-scale=1.0">
+        <title>401 Unauthorized</title>
+        <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap-icons@1.13.1/font/bootstrap-icons.min.css"
+              integrity="sha384-CK2SzKma4jA5H/MXDUU7i1TqZlCFaD4T01vtyDFvPlD97JQyS+IsSh1nI2EFbpyk" crossorigin="anonymous">
+        <link rel="stylesheet" href="https://static.kazutech.jp/l/css/error.css">
+        <link rel="stylesheet" href="https://static.kazutech.jp/l/css/error-protected.css">
+        <meta name="robots" content="noindex,nofollow">
+    </head>
+    <body class="error-protected">
+        <div class="error-container">
+            <h1 class="error-code"><i class="bi bi-lock"></i></h1>
+            <p class="error-message">パスワード保護</p>
+            <p class="error-description">
+                このリンクはパスワードで保護されています。<br>
+                パスワードを入力してください。
+            </p>
+
+            <form id="password-form" class="password-form">
+                <div class="form-group">
+                    <div class="password-field">
+                        <input
+                                type="password"
+                                id="password-input"
+                                name="password"
+                                class="password-input"
+                                placeholder="パスワードを入力"
+                                required
+                                autocomplete="off"
+                        >
+                        <button type="button" id="toggle-password" class="toggle-password" aria-label="パスワードの表示切替">
+                            <i class="bi bi-eye" aria-hidden="true"></i>
+                        </button>
+                    </div>
+                    <button type="submit" class="submit-button">
+                        送信
+                    </button>
+                </div>
+                <div id="error-message" class="form-error-message hidden-field"></div>
+            </form>
+
+            <footer class="error-footer">
+                <p>&copy; 2025 Kazuhiro Oka</p>
+            </footer>
+        </div>
+
+
+        <script {%- if script_nonce %} nonce="{{ script_nonce }}" {%- endif %}>
+          document.addEventListener('DOMContentLoaded', function () {
+            const form = document.getElementById('password-form');
+            const passwordInput = document.getElementById('password-input');
+            const errorMessage = document.getElementById('error-message');
+            const togglePasswordButton = document.getElementById('toggle-password');
+            const togglePasswordIcon = togglePasswordButton?.querySelector('i');
+
+            const nonce = '{{ request_nonce }}';
+            const default_error_message = '{{ default_error_message }}'
+
+            form.addEventListener('submit', async function (e) {
+              e.preventDefault();
+              if (!passwordInput.value || !passwordInput.value.match(/\S/g)) {
+                showError('パスワードを入力してください');
+                return;
+              }
+              const challenge = await crypto.subtle.digest('SHA-256', (new TextEncoder()).encode(passwordInput.value + '#' + nonce)).then(
+                  b => Array.from(new Uint8Array(b)).map((bb) => bb.toString(16).padStart(2, '0')).join(''))
+
+              const currentUrl = new URL(window.location.href);
+              currentUrl.searchParams.set('{{ challenge_query_key }}', challenge);
+              currentUrl.searchParams.set('{{ nonce_query_key }}', nonce);
+
+              window.location.href = currentUrl.toString();
+            });
+
+            if (default_error_message) {
+              showError(default_error_message);
+            }
+
+            function showError(message) {
+              errorMessage.textContent = message;
+              errorMessage.classList.remove('hidden-field');
+              passwordInput.classList.add('input-error');
+
+              passwordInput.animate([
+                {transform: 'translateX(0)'},
+                {transform: 'translateX(-10px)'},
+                {transform: 'translateX(10px)'},
+                {transform: 'translateX(-10px)'},
+                {transform: 'translateX(10px)'},
+                {transform: 'translateX(0)'}
+              ], {
+                duration: 400,
+                easing: 'ease-in-out'
+              });
+            }
+
+            function hideError() {
+              errorMessage.classList.add('hidden-field');
+              passwordInput.classList.remove('input-error');
+            }
+
+            passwordInput.addEventListener('input', function () {
+              if (!errorMessage.classList.contains('hidden-field')) {
+                hideError();
+              }
+            });
+
+            togglePasswordButton?.addEventListener('click', function () {
+              const isHidden = passwordInput.type === 'password';
+              passwordInput.type = isHidden ? 'text' : 'password';
+              togglePasswordIcon?.classList.toggle('bi-eye', !isHidden);
+              togglePasswordIcon?.classList.toggle('bi-eye-slash', isHidden);
+            });
+          });
+        </script>
+    </body>
+</html>
+
diff --git a/modules/aws_dynamodb/output.tf b/modules/aws_dynamodb/output.tf
index d5bdf2c..a27fd8c 100644
--- a/modules/aws_dynamodb/output.tf
+++ b/modules/aws_dynamodb/output.tf
@@ -1,3 +1,7 @@
 output "link_table" {
   value = aws_dynamodb_table.link_table
 }
+
+output "link_nonce_table" {
+  value = aws_dynamodb_table.link_nonce
+}
diff --git a/modules/aws_dynamodb/table.tf b/modules/aws_dynamodb/table.tf
index 5be593b..1995dab 100644
--- a/modules/aws_dynamodb/table.tf
+++ b/modules/aws_dynamodb/table.tf
@@ -17,3 +17,22 @@ resource "aws_dynamodb_table" "link_table" {
     type = "S"
   }
 }
+
+resource "aws_dynamodb_table" "link_nonce" {
+  name         = "Delibird-${var.environment}-DelibirdLinkNonceTable"
+  billing_mode = "PAY_PER_REQUEST"
+
+  deletion_protection_enabled = true
+
+  hash_key = "nonce"
+
+  attribute {
+    name = "nonce"
+    type = "S"
+  }
+
+  ttl {
+    attribute_name = "expired_timestamp"
+    enabled        = true
+  }
+}
diff --git a/modules/aws_iam/lambda_admin_portal.tf b/modules/aws_iam/lambda_admin_portal.tf
index 782e4f3..aab071b 100644
--- a/modules/aws_iam/lambda_admin_portal.tf
+++ b/modules/aws_iam/lambda_admin_portal.tf
@@ -54,6 +54,7 @@ resource "aws_iam_role_policy" "lambda_admin_portal" {
               "tag",
               "expiration_date",
               "expired_origin",
+              "passphrase",
               "query_omit",
               "query_whitelist"
             ]
diff --git a/modules/aws_iam/lambda_redirect_request.tf b/modules/aws_iam/lambda_redirect_request.tf
index a45ead0..b40d492 100644
--- a/modules/aws_iam/lambda_redirect_request.tf
+++ b/modules/aws_iam/lambda_redirect_request.tf
@@ -50,6 +50,33 @@ resource "aws_iam_role_policy" "lambda_redirect_request" {
           }
         }
       },
+      {
+        Effect = "Allow"
+        Action = [
+          "dynamodb:GetItem",
+          "dynamodb:PutItem",
+        ]
+        Resource = [
+          var.ddb_link_nonce_table.arn,
+        ]
+      },
+      {
+        Effect = "Allow"
+        Action = [
+          "dynamodb:UpdateItem",
+        ]
+        Resource = [
+          var.ddb_link_nonce_table.arn,
+        ]
+        Condition = {
+          "ForAllValues:StringEquals" = {
+            "dynamodb:Attributes" = [
+              "nonce",
+              "used_at",
+            ]
+          }
+        }
+      },
     ]
   })
 }
diff --git a/modules/aws_iam/variables.tf b/modules/aws_iam/variables.tf
index a402477..d0a28f0 100644
--- a/modules/aws_iam/variables.tf
+++ b/modules/aws_iam/variables.tf
@@ -10,6 +10,13 @@ variable "ddb_link_table" {
   })
 }
 
+variable "ddb_link_nonce_table" {
+  type = object({
+    name = string
+    arn  = string
+  })
+}
+
 variable "lambda_redirect_request" {
   type = object({
     name = string
diff --git a/modules/aws_lambda/function.tf b/modules/aws_lambda/function.tf
index c167d50..b11baa6 100644
--- a/modules/aws_lambda/function.tf
+++ b/modules/aws_lambda/function.tf
@@ -29,6 +29,8 @@ resource "aws_lambda_function" "redirect_request" {
       DELIBIRD_ENV           = var.environment
       ENV_VAR                = var.environment_var
       LINK_TABLE_NAME        = var.ddb_link_table.name
+      NONCE_TABLE_NAME       = var.ddb_link_nonce_table.name
+      NONCE_LIFETIME_SECONDS = var.protected_link_request_nonce_lifetime
       STATIC_RESOURCE_DIR    = "/opt/delibird/static"
       ALLOWED_DOMAIN         = join(",", var.allowed_domain)
       MAX_QUERY_KEY_LENGTH   = "100"
diff --git a/modules/aws_lambda/variables.tf b/modules/aws_lambda/variables.tf
index b73df13..906492b 100644
--- a/modules/aws_lambda/variables.tf
+++ b/modules/aws_lambda/variables.tf
@@ -34,6 +34,13 @@ variable "ddb_link_table" {
   })
 }
 
+variable "ddb_link_nonce_table" {
+  type = object({
+    name = string
+    arn  = string
+  })
+}
+
 variable "role_redirect_request" {
   type = object({
     name = string
@@ -57,6 +64,11 @@ variable "allowed_domain" {
   type        = list(string)
 }
 
+variable "protected_link_request_nonce_lifetime" {
+  description = "Lifetime of nonce for protected link requests in seconds"
+  type        = number
+}
+
 variable "reserved_concurrent_executions" {
   description = "Reserved concurrent executions for Lambda function (for cost and DDoS protection)"
   type        = number
diff --git a/modules/aws_s3/error_css.tf b/modules/aws_s3/stylesheet.tf
similarity index 65%
rename from modules/aws_s3/error_css.tf
rename to modules/aws_s3/stylesheet.tf
index aaf22a2..be5b23d 100644
--- a/modules/aws_s3/error_css.tf
+++ b/modules/aws_s3/stylesheet.tf
@@ -13,6 +13,21 @@ resource "aws_s3_object" "error_css" {
   etag = filemd5("${local.local_base_path}/css/error.css")
 }
 
+resource "aws_s3_object" "error_protected_css" {
+  # アップロード元(ローカル)
+  source = "${local.local_base_path}/css/error-protected.css"
+
+  # アップロード先(S3)
+  bucket = var.bucket_name
+  key    = "${var.remote_base_path}/css/error-protected.css"
+
+  # Content-Type の設定
+  content_type = "text/css"
+
+  # エンティティタグ (ファイル更新のトリガーに必要)
+  etag = filemd5("${local.local_base_path}/css/error-protected.css")
+}
+
 resource "aws_s3_object" "admin_portal_css" {
   # アップロード元(ローカル)
   source = "${local.local_base_path}/css/admin-portal.css"
diff --git a/s3/css/admin-portal.css b/s3/css/admin-portal.css
index 674ca4f..e5e7bcd 100644
--- a/s3/css/admin-portal.css
+++ b/s3/css/admin-portal.css
@@ -64,6 +64,10 @@
     max-width: 50px;
 }
 
+.tooltip-inner {
+    max-width: 400px;
+}
+
 .table-responsive {
     font-size: 0.9rem;
 }
@@ -114,4 +118,41 @@
 
 .bg-expired {
     background-color: #6f42c1;
-}
\ No newline at end of file
+}
+
+.password-field-wrapper {
+    position: relative;
+}
+
+.password-toggle-btn {
+    position: absolute;
+    top: 50%;
+    right: 10px;
+    transform: translateY(-50%);
+    background: transparent;
+    border: none;
+    cursor: pointer;
+    color: #6c757d;
+    padding: 4px 8px;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    z-index: 10;
+}
+
+.password-toggle-btn:hover {
+    color: #495057;
+}
+
+.password-toggle-btn:focus {
+    outline: none;
+    color: #0d6efd;
+}
+
+.password-toggle-btn i {
+    font-size: 1.1rem;
+}
+
+.password-input-field {
+    padding-right: 2.5rem;
+}
diff --git a/s3/css/error-protected.css b/s3/css/error-protected.css
new file mode 100644
index 0000000..10d6eec
--- /dev/null
+++ b/s3/css/error-protected.css
@@ -0,0 +1,140 @@
+body.error-protected {
+    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
+}
+
+body.error-protected .error-code {
+    font-size: 6rem;
+    color: #4facfe;
+}
+
+body.error-protected .error-code i {
+    font-size: 5rem;
+}
+
+.hidden-field {
+    display: none !important;
+}
+
+.password-form {
+    margin: 2rem 0;
+}
+
+.form-group {
+    display: flex;
+    flex-direction: column;
+    gap: 1rem;
+    align-items: center;
+}
+
+.password-field {
+    position: relative;
+    width: 100%;
+    max-width: 350px;
+}
+
+.toggle-password {
+    position: absolute;
+    top: 50%;
+    right: 12px;
+    transform: translateY(-50%);
+    background: transparent;
+    border: none;
+    cursor: pointer;
+    color: #777;
+    padding: 4px;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+}
+
+.toggle-password:focus-visible {
+    outline: 2px solid #4facfe;
+    border-radius: 4px;
+}
+
+.toggle-password i {
+    font-size: 1.1rem;
+}
+
+.password-input {
+    width: 100%;
+    max-width: 350px;
+    padding: 0.875rem 1rem;
+    font-size: 1rem;
+    border: 2px solid #e0e0e0;
+    border-radius: 8px;
+    transition: all 0.3s ease;
+    box-sizing: border-box;
+    padding-right: 2.75rem;
+}
+
+.password-input:focus {
+    outline: none;
+    border-color: #4facfe;
+    box-shadow: 0 0 0 3px rgba(79, 172, 254, 0.1);
+}
+
+.password-input.input-error {
+    border-color: #f5576c;
+}
+
+.password-input.input-error:focus {
+    box-shadow: 0 0 0 3px rgba(245, 87, 108, 0.1);
+}
+
+.submit-button {
+    width: 100%;
+    max-width: 350px;
+    padding: 0.875rem 2rem;
+    font-size: 1rem;
+    font-weight: 600;
+    color: white;
+    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
+    border: none;
+    border-radius: 8px;
+    cursor: pointer;
+    transition: all 0.3s ease;
+    box-shadow: 0 4px 15px rgba(79, 172, 254, 0.3);
+}
+
+.submit-button:hover {
+    transform: translateY(-2px);
+    box-shadow: 0 6px 20px rgba(79, 172, 254, 0.4);
+}
+
+.submit-button:active {
+    transform: translateY(0);
+    box-shadow: 0 2px 10px rgba(79, 172, 254, 0.3);
+}
+
+.submit-button:disabled {
+    background: #ccc;
+    cursor: not-allowed;
+    box-shadow: none;
+    transform: none;
+}
+
+.form-error-message {
+    color: #f5576c;
+    font-size: 0.875rem;
+    margin-top: 0.5rem;
+    text-align: center;
+    font-weight: 500;
+}
+
+@media (max-width: 600px) {
+    .password-input,
+    .submit-button {
+        max-width: 100%;
+    }
+
+    .password-field,
+    .password-input {
+        max-width: 100%;
+    }
+
+    .error-container {
+        padding: 2rem 1.5rem;
+    }
+}
+