Name: Implementing End To End Encryption For Messaging
Author: mukul975

Overview

End-to-end encryption (E2EE) ensures that only the communicating parties can read messages, with no intermediary (including the server) able to decrypt them. This skill implements a simplified version of the Signal Protocol's Double Ratchet algorithm, using X25519 for key exchange, HKDF for key derivation, and AES-256-GCM for message encryption.

When to Use

When deploying or configuring implementing end to end encryption for messaging capabilities in your environment
When establishing security controls aligned to compliance requirements
When building or improving security architecture for this domain
When conducting security assessments that require this implementation

Prerequisites

Familiarity with cryptography concepts and tools
Access to a test or lab environment for safe execution
Python 3.8+ with required dependencies installed
Appropriate authorization for any testing activities

Objectives

Overview

When to Use

When deploying or configuring implementing end to end encryption for messaging capabilities in your environment
When establishing security controls aligned to compliance requirements
When building or improving security architecture for this domain
When conducting security assessments that require this implementation

Prerequisites

Familiarity with cryptography concepts and tools
Access to a test or lab environment for safe execution
Python 3.8+ with required dependencies installed
Appropriate authorization for any testing activities

Component	Purpose	Algorithm
X3DH	Initial key agreement	X25519
Double Ratchet	Ongoing key management	X25519 + HKDF + AES-GCM
Sending Chain	Per-message encryption keys	HMAC-SHA256 chain
Receiving Chain	Per-message decryption keys	HMAC-SHA256 chain
Root Chain	Derives new chain keys on DH ratchet	HKDF

Implementing End To End Encryption For Messaging

Overview

When to Use

Prerequisites

Objectives

Implementing End To End Encryption For Messaging

Overview

When to Use

Prerequisites

Objectives

Key Concepts

Signal Protocol Components

Forward Secrecy

Security Considerations

Validation Criteria

1password

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