Encryption Technical Specification

Overview

CloudPaste uses client-side end-to-end encryption to ensure your data remains private and secure. When encryption is enabled, all text and images are encrypted in your browser before being sent to our servers. This means we never have access to your unencrypted data or your password.

                🛡️ Your data is encrypted before it leaves your device.

                The server only stores encrypted data and never sees your password or decrypted content.

Technical Specifications

Encryption Algorithm: AES-256-GCM (Advanced Encryption Standard)

Key Derivation: PBKDF2 (Password-Based Key Derivation Function 2)

Hash Function: SHA-256

Iterations: 100,000 (PBKDF2 iterations)

Key Length: 256 bits

Salt Length: 128 bits (randomly generated per encryption)

IV Length: 96 bits (randomly generated per encryption)

Implementation: Web Crypto API (native browser cryptography)

How It Works

Encryption Process

1

Enter Password

You provide a password

→

2

Key Derivation

PBKDF2 generates encryption key

→

3

Encrypt Data

AES-256-GCM encrypts content

→

4

Upload

Encrypted data sent to server

Step-by-step breakdown:

Random Salt Generation: A unique 128-bit salt is generated for each encryption operation
Random IV Generation: A unique 96-bit initialization vector (IV) is generated
Key Derivation: Your password is combined with the salt using PBKDF2 with 100,000 iterations to create a strong 256-bit encryption key
Encryption: The data is encrypted using AES-256-GCM with the derived key and IV
Data Packaging: The salt, IV, and encrypted data are combined and encoded in Base64
Upload: Only the encrypted package is sent to the server

Decryption Process

When you or someone with the password opens an encrypted channel:

Password Entry: The correct password must be provided
Data Download: Encrypted data is downloaded from the server
Extraction: Salt and IV are extracted from the encrypted package
Key Derivation: The same PBKDF2 process recreates the encryption key from the password and salt
Decryption: AES-256-GCM decrypts the data using the derived key and IV
Display: Decrypted content is displayed in your browser

Security Features

🔒 Client-Side Encryption

All encryption and decryption happens in your browser using the Web Crypto API. Your password and unencrypted data never leave your device.

🎲 Unique Encryption Per Operation

Each time data is encrypted, new random salt and IV values are generated. This means the same content encrypted twice produces completely different ciphertext, preventing pattern analysis.

🔐 Strong Key Derivation

PBKDF2 with 100,000 iterations makes brute-force password attacks computationally expensive. Even with a moderately strong password, attackers would need significant resources to crack the encryption.

✅ Authenticated Encryption

AES-GCM provides both confidentiality and authenticity. It ensures that encrypted data hasn't been tampered with, protecting against modification attacks.

🌐 Industry-Standard Algorithms

We use only well-established, peer-reviewed cryptographic algorithms (AES-256, PBKDF2, SHA-256) that are trusted by security experts worldwide.

What We Store

                On the server, we only store:
                Encrypted ciphertext (unreadable without your password)
A flag indicating the channel is encrypted
Metadata (upload timestamps, file sizes)

            

                ⚠️ We NEVER store:
                Your password
Your encryption keys
Your unencrypted data

            

Best Practices

Use a strong password: Choose a password with at least 12 characters, mixing letters, numbers, and symbols
Don't reuse passwords: Use a unique password for each encrypted channel
Share passwords securely: Send passwords through a different channel than the CloudPaste URL (e.g., encrypted messaging app)
Remember your password: If you lose your password, the data cannot be recovered - not even by us
Use HTTPS: Always access CloudPaste over HTTPS to prevent man-in-the-middle attacks

Limitations & Considerations

While our encryption is strong, please be aware of these considerations:

Password strength matters: Weak passwords can be cracked through brute-force attacks
Browser security: Your browser must be secure and free from malware
No password recovery: Lost passwords mean permanently lost data
Metadata is visible: File sizes, upload times, and the number of files are not encrypted
Channel URLs are not encrypted: Anyone with the channel URL can attempt to decrypt the data if they have the password

Open Source & Transparency

Security through obscurity is not security. Our encryption implementation uses standard Web Crypto APIs and can be audited by viewing the source code in your browser's developer tools.

🔐 Encryption Technical Specification