AES Encryptor/Decryptor - Secure Data Encryption Tool

Executive Summary

What is the AES Encryptor/Decryptor?

The AES Encryptor/Decryptor is a professional-grade cryptographic tool that implements Advanced Encryption Standard (AES) encryption, the same algorithm trusted by governments, financial institutions, and security professionals worldwide. This browser-based tool provides military-grade encryption (AES-256-GCM) for protecting sensitive data, ensuring confidentiality and integrity through authenticated encryption.

Who Should Use This Tool?

Primary Audiences:

Developers: Encrypt API keys, tokens, configuration files, and sensitive application data
Security Professionals: Secure communications, protect credentials, and encrypt sensitive documents
Business Users: Encrypt confidential business information, contracts, and proprietary data
Privacy-Conscious Individuals: Protect personal information, passwords, and private messages
Compliance Officers: Meet data protection requirements (GDPR, HIPAA, PCI-DSS)

Key Capabilities

✅ Military-Grade Encryption: AES-256-GCM provides 256-bit key strength with authenticated encryption ✅ Client-Side Processing: All encryption occurs in your browser - no data transmitted to servers ✅ Key Management: Secure key generation, storage, and import/export functionality ✅ Multiple Modes: Support for GCM, CBC, CTR modes with different security properties ✅ Format Flexibility: Output in Base64, Hex, or binary formats ✅ Batch Operations: Encrypt or decrypt multiple items efficiently ✅ Integrity Verification: Built-in authentication prevents tampering ✅ Export Options: Save encrypted data and keys securely

When to Use AES Encryption

Encrypting files before cloud storage upload
Protecting database fields containing sensitive information
Securing configuration files with credentials
Encrypting messages for secure communication
Protecting data at rest on disk or in databases
Complying with data protection regulations
Backing up sensitive information securely

Quick Start (30 Seconds)

Enter your plaintext in the input field
Generate or enter an encryption key (minimum 16 characters recommended)
Click “Encrypt” to transform your data
Copy the encrypted output and store your key securely
To decrypt: Paste encrypted data, enter the same key, click “Decrypt”

Security Note: Your encryption key is the only way to decrypt your data. Store it securely and never share it through insecure channels.

Feature Tour

1. Encryption Interface

Input Text Area

Large text field supporting up to 1MB of plaintext data
Syntax highlighting for common data formats
Character and byte count display
Paste from clipboard functionality
Clear input button for quick resets

Key Management Panel

🔑 Encryption Key Options:
├── Generate Random Key (recommended)
│   ├── 128-bit (16 bytes)
│   ├── 192-bit (24 bytes)
│   └── 256-bit (32 bytes) ⭐ Recommended
├── Enter Custom Key
│   └── Minimum 16 characters
└── Import Existing Key
    ├── From file
    └── From clipboard

Algorithm Selection

AES-256-GCM (default): Authenticated encryption, best security
AES-256-CBC: Traditional block cipher mode
AES-256-CTR: Counter mode for streaming data
AES-192-GCM: Faster processing, still very secure
AES-128-GCM: Maximum compatibility

2. Advanced Encryption Options

Initialization Vector (IV) Settings

Auto-generate random IV (recommended)
Custom IV for specific use cases
IV display and export options
Automatic IV prepending to ciphertext

Additional Authenticated Data (AAD)

Add context data for GCM mode
Enhance security without encrypting AAD
Useful for versioning and metadata

Padding Schemes

PKCS7 padding (default for CBC)
Zero padding
ISO/IEC 7816-4 padding
No padding (for specific block sizes)

3. Decryption Interface

Encrypted Data Input

Accepts Base64, Hex, or binary formats
Automatic format detection
Paste encrypted output directly
Import from file functionality

Key Verification

Visual key strength indicator
Key format validation
Wrong key detection with clear error messages
Key mismatch warnings

Decryption Results

Original plaintext display
Character encoding verification
Integrity check status
Successful decryption confirmation

4. Key Management Features

Secure Key Generation

// Example: Generate cryptographically secure key
Generate Key Button → Creates random 256-bit key
├── Uses Web Crypto API (crypto.getRandomValues)
├── Ensures cryptographic randomness
├── Displays key in multiple formats
└── Provides secure copy function

Key Storage Options

Browser Storage (encrypted with master password)
Download as File (password-protected)
Copy to Clipboard (with auto-clear)
QR Code Export (for mobile devices)

Key Import/Export

Export Formats:
├── Raw Binary (.key)
├── Base64 Text (.txt)
├── Hexadecimal (.hex)
└── JSON Key Bundle (.json)

5. Security Features

Privacy Protection

✅ All operations performed client-side
✅ No server communication
✅ No data logging or analytics
✅ Secure memory clearing after operations
✅ No key storage without explicit user action

Integrity Verification

Authentication tags in GCM mode
Tamper detection
Corruption alerts
Checksum validation

Visual Security Indicators

🔒 Encryption Status:
├── 🔓 Plaintext Visible
├── 🔐 Encrypting... (processing)
├── ✅ Encrypted Successfully
├── 🔑 Ready to Decrypt
└── ❌ Decryption Failed (check key)

6. Batch Processing

Multiple Item Encryption

Encrypt lists of items with same key
CSV import for bulk operations
Individual IV for each item
Batch export functionality

Batch Decryption

Decrypt multiple ciphertexts
Error handling for individual failures
Progress tracking
Export decrypted batch

Usage Scenarios

Scenario 1: Encrypting API Keys for Configuration Files

Challenge: Storing API keys in configuration files poses security risks if the repository is compromised.

Solution:

# Original config file
API_KEY=sk_live_1234567890abcdefghij
DATABASE_URL=postgresql://user:pass@localhost/db

# Encrypted version
API_KEY=ENC[hKj9mN3pQ6rS8tU0vX2y...]
DATABASE_URL=ENC[aB4cD6eF8gH1iJ3kL5m...]

Steps:

Open AES Encryptor/Decryptor
Generate a 256-bit encryption key
Encrypt each sensitive value separately
Replace plaintext values with encrypted versions
Store the encryption key securely (environment variable, key vault)
Decrypt at runtime when application starts

Benefits: Even if your repository is exposed, API keys remain protected.

Scenario 2: Secure File Backup

Challenge: Backing up sensitive documents to cloud storage without exposing contents.

Solution:

Document → Encrypt → Upload to Cloud
         ↓
    Store Key Locally or in Password Manager
         ↓
Download from Cloud → Decrypt → Original Document

Steps:

Copy file contents or convert to Base64
Encrypt with strong key
Save encrypted output to new file
Upload encrypted file to cloud storage
Store encryption key separately (not in cloud)
To retrieve: Download, decrypt with key

Use Cases: Financial records, legal documents, medical information, intellectual property.

Scenario 3: Encrypted Database Fields

Challenge: Protecting specific database columns containing sensitive user information.

Implementation:

// Before storing in database
const encryptedSSN = await encryptAES(userSSN, encryptionKey);
await db.users.update({ id: userId }, { ssn: encryptedSSN });

// When retrieving from database
const user = await db.users.findOne({ id: userId });
const decryptedSSN = await decryptAES(user.ssn, encryptionKey);

Best Practices:

Use different keys for different data types
Implement key rotation policies
Store keys in dedicated key management systems
Audit all encryption/decryption operations

Scenario 4: Secure Message Exchange

Challenge: Sending confidential information through insecure channels (email, chat).

Solution:

Sender:                      Receiver:
1. Write message       →     5. Receive encrypted message
2. Encrypt with key    →     6. Receive key (separate channel)
3. Send encrypted text →     7. Decrypt message
4. Send key separately →     8. Read original message

Steps:

Write your confidential message
Encrypt using AES tool
Send encrypted text via primary channel (email)
Send key via separate secure channel (phone, Signal)
Receiver decrypts using same key

Security Tip: Never send the key through the same channel as the encrypted message.

Scenario 5: Protecting Sensitive Configuration

Challenge: Development teams need access to configuration templates without exposing production secrets.

Solution:

// config.encrypted.json
{
  "database": {
    "host": "localhost",
    "username": "ENC[xY9zA1bC2dE3...]",
    "password": "ENC[fG4hI5jK6lM7...]"
  },
  "api": {
    "key": "ENC[nO8pQ9rS0tU1...]"
  }
}

// Decryption at application startup
const config = loadAndDecryptConfig('config.encrypted.json', process.env.CONFIG_KEY);

Team Workflow:

Encrypt all sensitive configuration values
Commit encrypted config to repository
Share decryption key through secure channel
Developers decrypt locally for testing
Production uses separate production key

Scenario 6: Complying with Data Protection Regulations

GDPR/HIPAA Compliance Requirements:

Encrypt personal data at rest
Implement access controls
Maintain audit trails
Support data portability

Implementation with AES Encryptor:

User Data Collection
    ↓
Immediate Encryption (AES-256-GCM)
    ↓
Encrypted Storage
    ↓
Audit Log Entry
    ↓
Access Request → Decrypt → Provide Data → Re-encrypt

Compliance Benefits:

✅ Satisfies encryption requirements
✅ Enables secure data portability
✅ Protects against unauthorized access
✅ Supports right to be forgotten (destroy keys)

Code Examples and Integration

JavaScript/Node.js Implementation

// Using Web Crypto API (browser)
async function encryptAES256GCM(plaintext, keyString) {
  // Convert key string to CryptoKey
  const keyData = new TextEncoder().encode(keyString.padEnd(32, '0').slice(0, 32));
  const key = await crypto.subtle.importKey(
    'raw',
    keyData,
    { name: 'AES-GCM' },
    false,
    ['encrypt']
  );
  
  // Generate random IV
  const iv = crypto.getRandomValues(new Uint8Array(12));
  
  // Encrypt data
  const encodedText = new TextEncoder().encode(plaintext);
  const ciphertext = await crypto.subtle.encrypt(
    { name: 'AES-GCM', iv: iv },
    key,
    encodedText
  );
  
  // Combine IV and ciphertext
  const combined = new Uint8Array(iv.length + ciphertext.byteLength);
  combined.set(iv);
  combined.set(new Uint8Array(ciphertext), iv.length);
  
  // Return as Base64
  return btoa(String.fromCharCode(...combined));
}

async function decryptAES256GCM(encryptedBase64, keyString) {
  // Convert key string to CryptoKey
  const keyData = new TextEncoder().encode(keyString.padEnd(32, '0').slice(0, 32));
  const key = await crypto.subtle.importKey(
    'raw',
    keyData,
    { name: 'AES-GCM' },
    false,
    ['decrypt']
  );
  
  // Decode Base64 and extract IV
  const combined = Uint8Array.from(atob(encryptedBase64), c => c.charCodeAt(0));
  const iv = combined.slice(0, 12);
  const ciphertext = combined.slice(12);
  
  // Decrypt
  try {
    const decrypted = await crypto.subtle.decrypt(
      { name: 'AES-GCM', iv: iv },
      key,
      ciphertext
    );
    
    return new TextDecoder().decode(decrypted);
  } catch (error) {
    throw new Error('Decryption failed - incorrect key or corrupted data');
  }
}

// Usage example
const sensitiveData = "Credit Card: 4532-1234-5678-9010";
const encryptionKey = "MySecureKey2025!@#$%";

const encrypted = await encryptAES256GCM(sensitiveData, encryptionKey);
console.log('Encrypted:', encrypted);
// Output: "rT3uY8kL5mN2pQ9sV6wX..."

const decrypted = await decryptAES256GCM(encrypted, encryptionKey);
console.log('Decrypted:', decrypted);
// Output: "Credit Card: 4532-1234-5678-9010"

Python Implementation

from Crypto.Cipher import AES
from Crypto.Random import get_random_bytes
import base64

def encrypt_aes_gcm(plaintext, key_string):
    # Ensure key is 32 bytes (256 bits)
    key = key_string.encode('utf-8').ljust(32, b'0')[:32]
    
    # Generate random nonce (IV)
    nonce = get_random_bytes(12)
    
    # Create cipher
    cipher = AES.new(key, AES.MODE_GCM, nonce=nonce)
    
    # Encrypt and get authentication tag
    ciphertext, tag = cipher.encrypt_and_digest(plaintext.encode('utf-8'))
    
    # Combine nonce + tag + ciphertext
    combined = nonce + tag + ciphertext
    
    # Return as Base64
    return base64.b64encode(combined).decode('utf-8')

def decrypt_aes_gcm(encrypted_base64, key_string):
    # Ensure key is 32 bytes (256 bits)
    key = key_string.encode('utf-8').ljust(32, b'0')[:32]
    
    # Decode Base64
    combined = base64.b64decode(encrypted_base64)
    
    # Extract components
    nonce = combined[:12]
    tag = combined[12:28]
    ciphertext = combined[28:]
    
    # Create cipher
    cipher = AES.new(key, AES.MODE_GCM, nonce=nonce)
    
    # Decrypt and verify
    try:
        plaintext = cipher.decrypt_and_verify(ciphertext, tag)
        return plaintext.decode('utf-8')
    except ValueError:
        raise Exception('Decryption failed - incorrect key or corrupted data')

# Usage
sensitive_data = "Social Security Number: 123-45-6789"
encryption_key = "MySecureKey2025!@#$%"

encrypted = encrypt_aes_gcm(sensitive_data, encryption_key)
print(f"Encrypted: {encrypted}")

decrypted = decrypt_aes_gcm(encrypted, encryption_key)
print(f"Decrypted: {decrypted}")

Integration with Password Management

Combine with our Password Strength Checker to ensure encryption keys meet security requirements:

function createEncryptionKey(userPassword) {
  // Validate password strength
  const strength = checkPasswordStrength(userPassword);
  
  if (strength.score < 60) {
    throw new Error('Encryption key too weak. Please use a stronger password.');
  }
  
  // Derive encryption key using PBKDF2
  const salt = crypto.getRandomValues(new Uint8Array(16));
  const keyMaterial = await crypto.subtle.importKey(
    'raw',
    new TextEncoder().encode(userPassword),
    'PBKDF2',
    false,
    ['deriveBits', 'deriveKey']
  );
  
  const encryptionKey = await crypto.subtle.deriveKey(
    {
      name: 'PBKDF2',
      salt: salt,
      iterations: 100000,
      hash: 'SHA-256'
    },
    keyMaterial,
    { name: 'AES-GCM', length: 256 },
    true,
    ['encrypt', 'decrypt']
  );
  
  return { key: encryptionKey, salt: salt };
}

Troubleshooting

Common Issues and Solutions

Issue 1: “Decryption Failed” Error

Symptoms: Error message when trying to decrypt previously encrypted data.

Possible Causes:

❌ Incorrect decryption key
❌ Corrupted ciphertext
❌ Wrong algorithm mode
❌ Missing or corrupted IV

Solutions:

1. Verify you're using the exact same key used for encryption
   - Keys are case-sensitive
   - Check for extra spaces or characters
   
2. Ensure encrypted data wasn't modified
   - Copy entire encrypted string including IV
   - Check for encoding issues (Base64 corruption)
   
3. Confirm algorithm mode matches
   - GCM encrypted data requires GCM for decryption
   - Check mode used during encryption
   
4. Test with known working example
   - Encrypt "test" with key "test123456789012"
   - Verify you can decrypt immediately

Issue 2: Key Management Confusion

Symptoms: Lost encryption keys, unable to decrypt important data.

Prevention:

Best Practices:
├── Store keys separately from encrypted data
├── Use password managers for key storage
├── Backup keys in multiple secure locations
├── Document key rotation procedures
└── Test decryption before discarding old keys

Recovery Options:

Check password manager archives
Review secure email for key backups
Search encrypted file metadata
Contact IT/security team for enterprise key recovery
Last Resort: If key is truly lost, data cannot be recovered

Issue 3: Performance with Large Files

Symptoms: Browser freezes or crashes when encrypting large amounts of data.

Workarounds:

// Break large data into chunks
async function encryptLargeFile(fileContent, key) {
  const chunkSize = 1024 * 1024; // 1MB chunks
  const chunks = [];
  
  for (let i = 0; i < fileContent.length; i += chunkSize) {
    const chunk = fileContent.slice(i, i + chunkSize);
    const encrypted = await encryptAES256GCM(chunk, key);
    chunks.push(encrypted);
    
    // Allow UI to update
    await new Promise(resolve => setTimeout(resolve, 0));
  }
  
  return JSON.stringify(chunks);
}

Recommendations:

Use native file encryption for files >10MB
Consider command-line tools for batch processing
Implement progress indicators for user feedback

Issue 4: Browser Compatibility

Symptoms: Tool doesn’t work in older browsers.

Requirements:

Web Crypto API support (Chrome 37+, Firefox 34+, Safari 11+)
Modern JavaScript (ES6+)
Sufficient memory for operations

Solutions:

Update browser to latest version
Use polyfills for older browsers
Switch to modern browser (Chrome, Firefox, Edge)

Issue 5: Character Encoding Issues

Symptoms: Decrypted text contains garbled characters.

Causes:

Encoding mismatch (UTF-8 vs UTF-16)
Special characters not properly handled
Binary data treated as text

Solutions:

// Ensure consistent encoding
const plaintext = new TextEncoder().encode(data); // Always UTF-8
const decrypted = new TextDecoder('utf-8').decode(result);

// For binary data, use appropriate handling
const binaryData = new Uint8Array(data);

Accessibility Features

Keyboard Navigation:

Tab - Navigate between input fields
Ctrl/Cmd + Enter - Execute encryption/decryption
Ctrl/Cmd + C - Copy results
Esc - Clear current operation

Screen Reader Support:

ARIA labels on all interactive elements
Status announcements for operations
Error message descriptions
Progress indicators with text alternatives

Visual Accessibility:

High contrast mode support
Adjustable font sizes
Color-blind friendly status indicators
Clear visual hierarchy

Internationalization:

Supports UTF-8 text in all languages
Unicode character handling
Right-to-left text support
Multi-byte character preservation

Frequently Asked Questions

1. Is my data sent to any servers?

No, absolutely not. All encryption and decryption operations happen entirely in your browser using JavaScript and the Web Crypto API. No data is transmitted to our servers or any third parties. You can verify this by:

Disconnecting from the internet and using the tool offline
Checking browser network activity (no requests sent)
Reviewing our open-source code

Your data never leaves your device.

2. How strong is AES-256 encryption?

AES-256 is military-grade encryption used by governments and security agencies worldwide. Key facts:

2^256 possible keys (~10^77 combinations)
Brute force attack: Would take billions of years with current technology
Quantum resistance: Even quantum computers would need millions of years
Industry standard: NIST approved, used by NSA for Top Secret data

AES-256 is considered secure for the foreseeable future.

3. What happens if I lose my encryption key?

Your data cannot be recovered. This is by design - strong encryption means:

No master keys exist
No backdoors or recovery mechanisms
No way to reset or recover keys
Mathematical impossibility to decrypt without the key

Prevention strategies:

Store keys in password managers
Maintain secure key backups
Document key locations
Use key derivation from memorable passwords
Test decryption before discarding keys

4. Can I use the same key for multiple encryptions?

Yes, but with considerations:

Safe practices:

✅ Same key, different IVs (our tool handles this automatically)
✅ Related data needing same access controls
✅ Performance-critical scenarios

Better practices:

🌟 Derive different keys from master key
🌟 Implement key rotation policies
🌟 Use separate keys for different security domains

Example key derivation:

// Derive specific keys from master key
const apiKeyEncryptionKey = deriveKey(masterKey, 'api-keys');
const dbPasswordKey = deriveKey(masterKey, 'database');

5. How is this different from HTTPS encryption?

Different purposes and layers:

Aspect	AES Encryptor	HTTPS/TLS
Scope	Data at rest	Data in transit
Duration	Indefinite	Session-based
Keys	User managed	Certificate-based
Use case	File/data encryption	Network communication
Persistence	Encrypted data stored	Decrypted on receipt

Combined use: Encrypt data with AES, then transmit over HTTPS for defense-in-depth.

6. What’s the difference between GCM and CBC modes?

AES-GCM (Galois/Counter Mode):

✅ Authenticated encryption (integrity + confidentiality)
✅ Parallel processing (faster)
✅ Detects tampering automatically
✅ Modern standard (recommended)
⚠️ IV reuse catastrophic

AES-CBC (Cipher Block Chaining):

✅ Well-established and tested
✅ Widely compatible
✅ Simpler implementation
⚠️ Requires separate authentication (HMAC)
⚠️ Sequential processing (slower)
⚠️ Padding oracle vulnerabilities

Recommendation: Use GCM unless specific compatibility requirements dictate otherwise.

7. Can I encrypt files, not just text?

Yes, with encoding:

File → Base64 Encode → Encrypt → Store
Retrieve → Decrypt → Base64 Decode → Original File

Process:

Convert file to Base64 using our Base64 Encoder
Encrypt the Base64 string
Store encrypted output
To retrieve: Decrypt, then decode Base64

Limitations:

Browser memory constraints (recommended <10MB)
Processing time for large files
Consider dedicated file encryption tools for large files

Best practice - Two-channel approach:

Channel 1 (Email/Cloud):
└── Send encrypted data

Channel 2 (Phone/Signal/In-person):
└── Share encryption key

Steps:

Encrypt your sensitive data
Send encrypted text via primary channel (email, Slack, etc.)
Send encryption key via separate secure channel (phone call, Signal message, in-person)
Recipient decrypts using the key

Security principle: Attacker needs access to both channels to decrypt data.

9. Is there a command-line version?

Browser tool only, but alternatives exist:

For command-line AES encryption:

# OpenSSL (cross-platform)
openssl enc -aes-256-gcm -in file.txt -out file.enc -k YourPassword

# GPG (cross-platform)
gpg --symmetric --cipher-algo AES256 file.txt

# Node.js script (using our code examples)
node encrypt.js --input file.txt --key YourKey --output file.enc

These produce compatible AES encryption for integration with our tool.

10. How often should I rotate encryption keys?

Depends on security requirements:

High-security environments (financial, medical):

Rotate every 90 days
Rotate after personnel changes
Rotate after suspected compromise

Medium-security (business data):

Rotate every 6-12 months
Rotate after major breaches in industry
Rotate when employees leave

Personal use:

Rotate annually
Rotate if password managers compromised
Rotate if device stolen/lost

Key rotation process:

Generate new encryption key
Decrypt data with old key
Re-encrypt with new key
Securely delete old key
Update key storage locations

References and Additional Resources

Internal Gray-wolf Tools

Complementary Security Tools:

Password Strength Checker: Validate encryption key strength before use
Hash Generator: Generate secure hashes for password storage and integrity verification
RSA Key Generator: Create asymmetric encryption keys for key exchange scenarios
Base64 Encoder: Encode binary data and files for encryption processing
UUID Generator: Generate unique identifiers for encryption contexts and sessions

Educational Resources

Learn More About Cryptography:

Encryption Fundamentals Guide
Symmetric vs Asymmetric Encryption
Key Management Best Practices
Cryptographic Algorithm Selection
Compliance and Regulation Guide

External Documentation

Standards and Specifications:

NIST Advanced Encryption Standard (AES) - FIPS 197
Web Crypto API Specification - W3C
Cryptographic Best Practices - OWASP
Key Management Guidelines - NIST SP 800-57

Last updated: November 3, 2025 | Tool Version: 2.1.0 | Maintained by Gray-wolf Security Team

Executive Summary

What is the AES Encryptor/Decryptor?

Who Should Use This Tool?

Key Capabilities

When to Use AES Encryption

Quick Start (30 Seconds)

Feature Tour

1. Encryption Interface

2. Advanced Encryption Options

3. Decryption Interface

4. Key Management Features

5. Security Features

6. Batch Processing

Usage Scenarios

Scenario 1: Encrypting API Keys for Configuration Files

Scenario 2: Secure File Backup

Scenario 3: Encrypted Database Fields

Scenario 4: Secure Message Exchange

Scenario 5: Protecting Sensitive Configuration

Scenario 6: Complying with Data Protection Regulations

Code Examples and Integration

JavaScript/Node.js Implementation

Python Implementation

Integration with Password Management

Troubleshooting

Common Issues and Solutions

Issue 1: “Decryption Failed” Error

Issue 2: Key Management Confusion

Issue 3: Performance with Large Files

Issue 4: Browser Compatibility

Issue 5: Character Encoding Issues

Accessibility Features

Frequently Asked Questions

1. Is my data sent to any servers?

2. How strong is AES-256 encryption?

3. What happens if I lose my encryption key?

4. Can I use the same key for multiple encryptions?

5. How is this different from HTTPS encryption?

6. What’s the difference between GCM and CBC modes?

7. Can I encrypt files, not just text?

8. How do I securely share encrypted data?

9. Is there a command-line version?

10. How often should I rotate encryption keys?

References and Additional Resources

Internal Gray-wolf Tools

Educational Resources

External Documentation