| **Protocol** | **Description** | **QKD Impact (Yes/No)** | **PQC Impact (Yes/No)** | **Crypto Agility Consideration** |
| ----------------------------------------------------------------------- | ----------------------------------------------------------------------- | ----------------------- | ----------------------- | ------------------------------------------------------------------------------------------------------------------------ |
| **TLS/SSL (Transport Layer Security)** | Protocol for securing communication between clients and servers. | No | Yes | TLS requires upgrades to support PQC algorithms as part of ongoing cryptographic transitions |
| **3-D Secure** | Authentication protocol for online card transactions. | No | Yes | Integrating PQC would require phased upgrades and careful handling of legacy systems |
| **EMV (Europay, Mastercard, Visa)** | Chip-based payment standard for secure transactions at point-of-sale. | No | No | EMV standards may not directly integrate PQC but must ensure encryption schemes remain secure during future transitions. |
| **ISO 20022** | Messaging standard for financial transactions between banks. | No | No | Crypto agility is crucial for ensuring smooth algorithm upgrades without disrupting message processing |
| **SWIFT (Society for Worldwide Interbank Financial Telecommunication)** | Messaging network for secure fund transfers internationally. | Yes | Yes | SWIFT may adopt a hybrid approach with QKD for secure inter-bank communication while preparing for PQC |
| **HSM (Hardware Security Module)** | Physical devices for managing and securing cryptographic keys. | Yes | Yes | HSMs need to be adaptable for new cryptographic standards as part of a crypto agile architecture |
| **PGP (Pretty Good Privacy)** | Encryption protocol often used for email and file encryption. | No | Yes | Needs integration with PQC-compatible algorithms while maintaining compatibility with existing implementations. |
| **AES (Advanced Encryption Standard)** | Symmetric encryption algorithm for securing data. | No | Yes | Symmetric key lengths might need to be doubled to maintain security against quantum threats |
| **RSA (Rivest-Shamir-Adleman)** | Asymmetric encryption for digital signatures and key exchange. | No | Yes | Migration to quantum-safe alternatives is essential due to vulnerabilities to Shor's algorithm |
| **ECC (Elliptic Curve Cryptography)** | Cryptographic method for encryption and digital signatures. | No | Yes | Vulnerable to quantum attacks; must transition to quantum-safe replacements |
| **IPSec (Internet Protocol Security)** | Secures IP communications by authenticating and encrypting each packet. | No | Yes | Updates needed to integrate PQC without impacting network performance. |
| **OAuth2** | Authorization framework for granting access to resources. | No | Yes | Requires compatibility with post-quantum cryptographic algorithms during transitions. |
| **S/MIME (Secure/Multipurpose Internet Mail Extensions)** | Protocol for secure email communication. | No | Yes | Requires phased implementation of PQC to maintain encrypted email integrity. |
| **Tokenization** | Replaces sensitive data with unique identifiers, protecting card data. | No | No | Minimal impact from QKD/PQC but must maintain compatibility with underlying cryptographic systems. |
| **MQTT (Message Queuing Telemetry Transport)** | Lightweight messaging protocol often used in IoT applications. | No | Yes | Critical to update for PQC readiness, ensuring security in a post-quantum environment. |