Fortune recently reported on the story of a young man who died unexpectedly in Colorado, leaving behind a small fortune in bitcoin investments that he had been accumulating unbeknownst to his family. When the man died, his family not only had to face the loss of life, but they also had to sort out how to find and gain access to the cryptocurrency itself. How should investors reconcile the security and privacy which are associated with digital currencies and which are normally considered to be assets and reasons for investing with the possibility that those cryptocurrencies will be inaccessible if the investor dies unexpectedly? (Related: How Do You Pass on Your Bitcoin When You Die?)

Cryptocurrencies Too Secure?

One of the major draws of cryptocurrencies like bitcoin is that they are backed by powerful cryptography. They are incredibly secure, with transactions conducted and rcorded anonymously and multiple layers of privacy and protection for digital currency wallets. This helps to secure an investors assets, but it can make them too secure when families and estate planners are attempting to access them.

Most bitcoin wallets rely on a set of random characters known as a “public key” for transactions. The public key is the way that others specify where to send and receive payments. The “private key,” on the other hand, is a user’s access point, a type of password for the wallet and its contents.

What Happens Without the Private Key?

If a bitcoin owner dies without being able to share his private key, his heirs may discover a wallet and not be able to access its holdings. Investors are cautioned to share their private keys with loved ones and trusted acquaintances by writing them down in a secure location or saving the key with a commercial service tasked with managing access codes.

Still, if executors to an estate do not recognize a private key to a bitcoin wallet for what it is, there’s a chance that it will be discarded without the assets having been accessed. For those reasons, a specialized commercial service may be the best option. These services will not only guard the access codes, but they will also know how to share the information with executors and next of kind should an investor die without transmitting that knowledge. In the case of the man from Fortune’s story, for example, his family worked with Coinbase, the popular wallet service, in order to be able to confirm their relationship with the man and gain access to the wallet. Nonetheless, like investors of a previous generation stashing away cash or paper stock certificates in hidden places, it’s likely that some cryptocurrency assets are going to go undiscovered, with thousands or even millions of dollars stashed away, inaccessible and unknown.