Most cryptocurrency users believe that placing their funds in cold storage means using a paper wallet. The method certainly has its benefits, yet it features a major problem – if someone sees your QR code, passphrase seed or private key, they can gain access your address and funds. Believe it or not, there’s a way to avoid this hassle using one of the most conventional means of diffusing information – sound.

Bitcoin has some sort of James Bond feel to it. Secret keys, anonymity, encryption, and the ability to send money worldwide instantly and support the growing economy are all great.

Sound Wallet takes this underlying spy theme to a whole new level by using a BIP38 encrypted key and transforming it into a sound file. Casual listeners will see it as the most static sound; however, if you listen to it with the AndroSpectro app out of the static, the characters that encompass the encrypted key will emerge.

A closer look at the Bitcoin Sound Wallet

The Bitcoin Sound Wallet was created by a Bitcointalk user, under the pseudonym krach. He says that the wallet is “just like a paper wallet in an audio form.” All you have to do to get yours is to send krach an email and mention the type of wallet you’d like to have encrypted - .wav, CD or vinyl record. The record option is surely the coolest version of the three:

“This record was hand shaped and individually cut in real time using a vintage 1940s Presto 75A recording lathe. It is a unique piece. It is not the same as a traditional pressed record. It was not made in a factory. It was hand carved from an 8ft sheet of polycarbonate plastic, shaped, sanded, waxed and cut in real time by one person.”

At the start of the record, there’s a burst of gentle static that comprises the key. Afterwards, there’s a smooth transition of the recording into some rough electro music. It’s a pretty ingenious idea, and if somebody listens to the record collection, they will think it’s just another ambiguous recording. Hiding a valuable key in plain sight has never been easier, and it’s safe to say that the elaborately constructed and conceived wallet feels much like a work of art.

Storing private keys safely and securely

The Sound Wallet system permits a device that’s completely offline “to jump the air gap to a less secure device” like a computer connected to the web. This features a range of options to store private keys: records are considered the best archive format. Users can add them to their record crate, frame it and hang them on their walls without anyone ever knowing that there’s a private key embedded into the audio. The Sound Wallet website highlights:

“Records are the ultimate archive format. You could add the record to your record crate, put it in a frame and hang it on your wall, or store it in your safe. Where we are at now: We have been able to embed a private key in into audio and then read the private key using a spectroscope app on an android phone. The audio is about 30 seconds to one minute of noise for one key.”

Unlike burning a DVD or a CD, recording vinyl is a lot more challenging and expensive. It demands specialized hardware like a turntable, record lathe, and blanks. Even though the project didn’t reach its crowdfunding target, it looks like the Sound wallets are now in production.

Right now, a 7’’ vinyl wallet costs 0.09 bitcoins, while a CD wallet costs 0.02 bitcoins.