Cold Storage vs. Hot Storage

"Cold" and "hot" sound like they describe temperature, so what do they actually describe here? The terms are about network exposure, not heat. Cold storage means keys are generated and held on a device that has never connected to a network. Hot storage means keys live on a device or app that stays connected. It's the difference between cash locked in a safe at home and cash carried in your everyday wallet — one takes a deliberate trip to reach, the other is on hand for whatever comes up.

Cold Storage

• Offline Key Generation: keys are created and stored on a device that has never touched a network.
• Minimal Exposure Surface: with no network path in or out, there's far less for an outside party to reach.
• Deliberate Access: using the keys means physically retrieving the device, which adds friction on purpose.

Hot Storage

• Connected Key Storage: keys are held on a device or app that stays online.
• Immediate Availability: ready to sign the moment it's needed, with no retrieval step in the way.
• Broader Attack Surface: an always-on connection opens more paths for something to go wrong.

The real distinction isn't how the keys get used day to day — it's whether the device holding them was ever reachable over a network at all. For how this plays out in actual devices, see Hardware vs. Software Wallets.