Data-only USB cables

December 19, 2024

Data-only USB cables are actually designed to allow only power transfer, not data transfer. These cables, also known as “charge-only” cables, lack the data transfer (D+) and data receive (D-) wires found in standard USB cables[1]. Using these cables can help prevent malicious payloads from being delivered via USB, as they physically lack the capability to transmit data.

Identifying Data-Only USB Cables

To ensure you're using a data-only cable:

Physical examination: Data-only cables tend to be slightly thinner than standard USB cables due to having fewer internal wires[1].
Functionality testing: Connect a device to your computer using the cable. If you cannot transfer files or the device is not recognized for data purposes, it's likely a data-only cable[1].
Purchase from reputable sources: Some manufacturers, like PortaPow, specifically produce data-only cables[3].

Benefits of Using Data-Only USB Cables

Enhanced security: These cables physically prevent data transfer, protecting against malware injection and unauthorized data access[5][6].
Safe charging in public places: You can charge your devices at public USB ports without risking data theft or “juice jacking”[3].

Considerations

Some devices may charge slower or not at all with data-only cables, as they rely on data pins for negotiating higher power delivery[7].
For maximum protection, combine the use of data-only cables with other security measures like USB blocking software and user education[5][6].

By using data-only USB cables in situations where you only need to charge devices, you can significantly reduce the risk of USB-based attacks while still maintaining the convenience of USB charging.

TL;DR.: Data-Only USB Cables: These cables are designed to only allow data transfer and power, without enabling any other USB functionalities. This can help prevent malicious payloads from being delivered via USB.

Citations: [1] https://support.konnected.io/how-to-tell-a-usb-charge-only-cable-from-a-usb-data-cable [2] https://www.coro.net/blog/why-usb-attacks-are-back-and-how-to-prevent-them [3] https://www.reddit.com/r/UsbCHardware/comments/1gbnvr4/any_240w_usb_c_to_usb_cables_without_data/ [4] https://cabletimetech.com/blogs/knowledge/not-all-usb-c-cables-are-created-equal-a-pros-guide [5] https://www.manageengine.com/device-control/badusb.html [6] https://www.redzonetech.net/blog-posts/bad-usb [7] https://electronics.stackexchange.com/questions/140225/how-can-i-tell-charge-only-usb-cables-from-usb-data-cables [8] https://www.opswat.com/blog/the-danger-of-a-usb-device-and-keystroke-injection-attack [9] https://news.ycombinator.com/item?id=42436936 [10] https://www.reddit.com/r/UsbCHardware/comments/119bx6s/how_to_easily_tell_whether_a_usbc_cable_is/ [11] https://securitybase.com.au/blogs/usb-hacking/public-usb-charging-risk-using-a-usb-data-blocker