I was curious to know if anyone knows of any bitcoin business that stores people's wallets offline?
I'm looking to diversify my backup methods for cold storage and am wanting to send my backups to a company that can store it for me securely.
In my opinion trusting a third party with your Bitcoin savings is kind of against the grain of Bitcoin.
It makes perfect sense to keep day to day amounts on hot wallets either on your phone or online by using services such as Coinbase, Blockchain.info, Circle and their likes. These companies offer various cold storage options (e.g. coinbase vault) and there are other vendors that specialize in cold storage solutions, e.g. xapo
All these are viable options and have a place on the ever denser continuum of options to store bitcoins, and in all these cases you surrender some control over your bitcoins for the benefit of simplicity and ease of use. However, part of the appeal of Bitcoin is the fact that by design you can maintain 100% control over your bitcoins. If you choose to do so, let me recommend CoinCooler (disclosure: I'm the founder).
CoinCooler helps you generate and encrypt digital files containing cold storage addresses and keys in a way that is guaranteed to be 100% offline. It also includes splitting the encryption password into shares (as was recommended above by Christopher). Basically, its a tool that helps you perform cold storage of bitcoins in a way that is easy and secure so that, hopefully, you will consider doing it yourself and not rely on a third party.
Safety deposit boxes, possibly multiple boxes at different banks plus the usage of Shamir's Secret Sharing, would seem to be the best option.
I'm not aware of any other individual-oriented secure storage businesses (e.g. Iron Mountain for individuals; Iron Mountain and similar businesses seem to be mostly for largish-scale storage / B2B).
Implementations of Shamir's Secret Sharing include this one by Lennart Poettering which is often available under the package name of
ssss in many Linux distros (including Debian and Ubuntu), and also the Armory bitcoin wallet.
There are also many options for storing your bip 38 encrypted private keys on physical coins. Many of them are DIY options including www.mycryptovault.net They allow you full control of your bitcoin cold storage!