---
title: Encrypt PDF with password
description: Add AES-256 password protection to PDF files using filename-based password rules.
category: File Transformations
tags: [pdf, encrypt, password, files]
---

# Encrypt PDF with password

## **Description**

The **Encrypt PDF with password** activity applies password protection to input PDF files. Passwords are selected using regex-based rules matched against each file name. Files that are already protected are returned unchanged with an error message, while files with no matching rule are skipped and returned unchanged.

### **Supported Features**

- **Multiple file processing**: Processes each input file independently.
- **Regex-based password rules**: Match file names and choose the password to apply.
- **AES-256 encryption**: Uses PDF password encryption with AES 256-bit encryption.
- **Already-protected detection**: Detects encrypted PDFs and does not re-encrypt them.
- **Invalid PDF handling**: Reports invalid or corrupt PDF files.
- **Unmatched file passthrough**: Files without a matching password rule are returned unchanged.

---

## **Input**

| Type | Required | Description |
| --- | --- | --- |
| Files | Yes | PDF files to encrypt. |

### **Input Scenarios**

#### **1. Unprotected PDF With Matching Rule**

```json
{
  "Files": [
    { "FileName": "invoice-001.pdf", "FullPath": "C:/Work/invoice-001.pdf" }
  ]
}
```

#### **2. Unprotected PDF With No Matching Rule**

The file is skipped and returned unchanged.

#### **3. Already Protected PDF**

The file is returned unchanged and the activity records `Already protected: <file>`.

---

## **Output**

| Field | Type | Description |
| --- | --- | --- |
| Files | Array | Encrypted PDF files, unchanged already-protected files, or unchanged files skipped because no rule matched. |
| Errors | Array | Errors for already protected files, invalid PDFs, missing files, or processing failures. |

### **Output Behavior**

- If at least one file is returned and errors exist, the activity returns success with errors.
- If no files are returned and errors exist, the activity returns failure.
- Encrypted files are written to the workflow base working folder using the original file name.

---

## **Configuration Fields**

| Field Name | Type | Required | Description |
| --- | --- | --- | --- |
| Password rules | Object Array | Yes | List of filename matching rules. Each rule contains `FilePattern` and `Password`. The first matching rule is used. |
| FilePattern | Text | Yes | Regex pattern matched against the input file name. Matching is case-insensitive. |
| Password | Text | Yes | Password used as the PDF document-open password for matching files. |

### **Conditional Field Rendering Rules**

No conditional configuration fields are defined for this activity.

---

## **Sample Configuration**

| FilePattern | Password |
| --- | --- |
| `^invoice-.*\.pdf$` | `Invoice@2026` |
| `^statement-.*\.pdf$` | `Statement@2026` |

---

## **Sample Output**

```json
{
  "Files": [
    {
      "FileName": "invoice-001.pdf",
      "FullPath": "C:/Workflow/invoice-001.pdf",
      "Size": 50124
    },
    {
      "FileName": "terms.pdf",
      "FullPath": "C:/Work/terms.pdf",
      "Size": 11020
    }
  ],
  "Errors": [
    "Already protected: statement-jan.pdf"
  ]
}
```