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2025-03-06 23:51:26 R. Bishop: Initial Commit| /dev/null .. communications/industry specific/f2f.md | |
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| + | # F/2F Card Reader Format & Wiring |
| + | |
| + | ## Understanding F/2F (Frequency to Frequency) Protocol |
| + | |
| + | **F/2F (Frequency-to-Frequency)** is an access control communication format used in legacy and specialized security systems. Unlike standard Wiegand or OSDP protocols, F/2F **modulates credential data into frequency variations** to transmit information between a card reader and the access control panel. It is commonly found in **older security infrastructures and military or government applications** where tamper resistance and offline functionality are critical. |
| + | |
| + | F/2F was originally developed as an **alternative to Wiegand** and remains in use in **proprietary security systems** requiring compatibility with legacy hardware. |
| + | |
| + | --- |
| + | |
| + | ## Why F/2F is Used |
| + | |
| + | F/2F is still in operation today due to its: |
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| + | - **Legacy System Compatibility** → Many older access control panels still rely on F/2F communication. |
| + | - **Tamper Resistance** → More difficult to spoof or intercept compared to Wiegand. |
| + | - **Simple Implementation** → Requires only a few signal lines for communication. |
| + | - **No Data Encryption Requirements** → Can operate in offline environments where encryption is not required. |
| + | |
| + | However, **F/2F lacks modern security features** like encryption and bidirectional communication, making it vulnerable to interception or replay attacks. |
| + | |
| + | --- |
| + | |
| + | ## How F/2F Works |
| + | |
| + | F/2F operates by encoding **binary data** as **frequency shifts** rather than direct voltage pulses. Each bit of data is transmitted as a **high or low frequency pulse**, which the controller interprets as `1` or `0`. |
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| + | ### **F/2F Data Transmission Process** |
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| + | 1. **Card is Presented** → The reader scans the card and extracts its credential data. |
| + | 2. **Bit Encoding** → The credential data is converted into a frequency-modulated signal. |
| + | 3. **Transmission to Panel** → The controller deciphers the frequency shifts and reconstructs the binary data. |
| + | 4. **Validation & Access Decision** → The panel checks the credentials against a stored database to permit or deny access. |
| + | |
| + | This frequency-based approach allows **F/2F to function reliably over long distances** but is **more susceptible to interference** compared to modern encrypted protocols. |
| + | |
| + | --- |
| + | |
| + | ## How F/2F is Wired |
| + | |
| + | F/2F requires **dedicated signal lines** for data transmission, but wiring differs between **supervised and unsupervised modes**. |
| + | |
| + | ### **Unsupervised F/2F Wiring** |
| + | |
| + | | Wire Colour | Function | |
| + | | ----------- | ---------------------------------------------------- | |
| + | | **Red** | +12V DC Power (Optional, if not powered separately) | |
| + | | **Black** | Ground (GND) | |
| + | | **Green** | Data (Frequency Modulated Output) | |
| + | | **White** | Clock Signal (Optional, depending on implementation) | |
| + | |
| + | **Unsupervised mode** does not provide monitoring for **reader tampering or communication failures**, making it less secure. |
| + | |
| + | ### **Supervised F/2F Wiring** |
| + | |
| + | | Wire Colour | Function | |
| + | | ----------- | ------------------------------------- | |
| + | | **Red** | +12V DC Power (Optional) | |
| + | | **Black** | Ground (GND) | |
| + | | **Green** | Data (Frequency Modulated Output) | |
| + | | **White** | Clock Signal (Optional) | |
| + | | **Blue** | Reader Supervision (Tamper Detection) | |
| + | | **Yellow** | Door Status (For advanced monitoring) | |
| + | |
| + | **Supervised F/2F mode** includes **tamper detection and communication monitoring**, improving security and reliability. If a tamper event is detected, the controller can trigger **alarms or disable the compromised reader**. |
| + | |
| + | --- |
| + | |
| + | ## Supervised vs. Unsupervised F/2F |
| + | |
| + | | Feature | Supervised F/2F | Unsupervised F/2F | |
| + | | --------------------- | ------------------------- | ------------------------- | |
| + | | **Tamper Detection** | ✅ Yes | ❌ No | |
| + | | **Reader Monitoring** | ✅ Yes | ❌ No | |
| + | | **Security Level** | 🔒 High | ⚠️ Low | |
| + | | **Wiring Complexity** | ⚠️ More Wires | ✅ Simpler Setup | |
| + | | **Common Use Case** | Government, High Security | Legacy Commercial Systems | |
| + | |
| + | Supervised F/2F is the **preferred option for modern implementations** where **tamper detection and fault monitoring** are critical. |
| + | |
| + | --- |
| + | |
| + | ## Security Considerations |
| + | |
| + | Although F/2F provides some tamper resistance, it has several security weaknesses: |
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| + | - **No Encryption** → Data is transmitted in an unencrypted format. |
| + | - **Replay Attacks** → Captured frequency signals can be replayed to gain unauthorized access. |
| + | - **Limited Interoperability** → Many modern access control panels do not support F/2F. |
| + | - **Susceptible to Interference** → Nearby electronic noise can disrupt frequency-based transmission. |
| + | |
| + | To improve security, organizations should consider **migrating to modern encrypted protocols such as OSDP** or using **multi-factor authentication** to supplement F/2F systems. |
| + | |
| + | --- |
| + | |
| + | ## Migration Considerations |
| + | |
| + | Organizations using F/2F should evaluate upgrading to **OSDP or encrypted Wiegand alternatives**. The migration process typically involves: |
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| + | 1. **Identifying Existing Infrastructure** → Determine if legacy F/2F readers can be replaced with modern smart card readers. |
| + | 2. **Upgrading to Secure Protocols** → Transition to **OSDP with AES encryption** for enhanced security. |
| + | 3. **Deploying Multi-Technology Readers** → Support both **legacy F/2F and modern credentials** for a phased migration. |
| + | 4. **Implementing Tamper Detection & Monitoring** → Ensure access control systems can detect and respond to reader tampering. |
| + | |
| + | **Multi-technology readers** allow organizations to **gradually phase out F/2F systems** while maintaining compatibility with legacy infrastructure. |
| + | |
| + | --- |
| + | |
| + | ## Final Thoughts |
| + | |
| + | **F/2F is a legacy access control protocol with limited security features, making it vulnerable to modern attack methods.** Organizations should: |
| + | |
| + | ✅ **Evaluate security risks associated with F/2F-based systems.**\ |
| + | ✅ **Upgrade to modern encrypted credential formats such as OSDP.**\ |
| + | ✅ **Use tamper detection and monitoring to enhance security.** |
| + | |
| + | By transitioning from **F/2F to secure communication protocols**, businesses can **future-proof their access control infrastructure while reducing the risk of unauthorized access**. |