06 Aug


Bitcoin cold storage made easy. Create and encrypt Private Keys offline, download them to USB sticks and keep them in safe places of your choice (including cloud storage). Protect yourself from password loss and ensure ownership transfer to heirs using advanced cryptographic techniques.


The Problem

Bitcoin storage is a challenge. One needs to balance between security, trust, ease of use, availability and retrievability. 

Common Solutions

Online storage of bitcoins can be very easy to use but raises security issues associated with trusting an external party as well as a plethora of online security weaknesses, from viruses and keyloggers, through spyware and all the way to hardware backdoors.
Storing your bitcoins on a pc or a smartphone removes the need to trust an external party, but keeps you exposed to all the online security threats described above.

It is considered a best practice in the Bitcoin community to keep only a small amount of bitcoins on hot wallets (=connected to the internet) and the bulk of your coins in cold storage (=the private key never touches the internet).

The CoinCooler Solution

CoinCooler offers a digital cold storage solution, that is:

  • Highly secure
  • Easy to use
  • Highly Retrievable
  • Affordable

CoinCooler is an application running on an offline Raspberry Pi. The Raspberry Pi is a cheap ($25-$35) full fledged linux computer, created in the UK for educational purposes. Because the Raspberry Pi is so cheap, it makes sense to use it as an offline computer dedicated to cold storage, instead of investing in a laptop or a pc.

CoinCooler creates a list of Bitcoin Addresses and their associated Private Keys and encrypts that list with industrial strength 256-bit-key encryption. This process happens offline on the raspberry pi computer without ever having contact with the internet.

CoinCooler makes the list of private keys available to download both in unencrypted format (It is considered a best practice to keep an unencrypted copy) and in an encrypted format. Make copies and store them in various places of your choice. In particular, the encrypted file can be uploaded to cloud storage without compromising security, a fact that greatly enhances the availability and retrievability of your cold storage files.

When the time comes and you need to use your stored coins, you can upload your cold storage files using the CoinCooler interface, retrieve the private keys and use one of many available online services to transact your coins.

Advanced features allow you to use cryptographic techniques to take some measures that reduce the probability of password loss and give your proper heirs the ability to access your stored bitcoins in case you are no longer around with minimal risk of abuse.

An online demo of the application is available.

Inquiries are welcomed at