Technical Summary of the CRS-19 ISS Mission
Over the past year, the SpaceChain Technical Team has been focused on creating and launching a Bitcoin multisig payload to the International Space Station (ISS). This payload will demonstrate new levels of cybersecurity for transactions and new paradigms in asset custody.
In a standard terrestrial blockchain transaction, one private key is used to complete a transaction which is then broadcast to the network. If that private key becomes known by a malicious entity, all of the funds can be lost. Multisig (multisignature) technology requires more than one private key approval in order to authorise a transaction, rendering the transaction vastly more secure than standard single-signature methods. Furthermore, multisig mechanism provides an effective way of managing accounts/assets that are jointly held by multiple parties. The SpaceChain implementation adds the remoteness and security of low-Earth orbit infrastructure to multisig to create something entirely new.
A SpaceChain multisig transaction looks like this: a user creates a space multisig wallet and then initiates a transaction. Subsequently, the transaction is approved with his/her private key. The transaction is then sent up to the low-Earth orbit infrastructure, in this case the ISS, and the payload there approves the transaction with the private key that is generated and stored there. The transaction is then sent down to be broadcasted to the wider network to be included in the blockchain.
With the SpaceChain payload, it is highly improbable that an attacker can gain physical access to the device, since it runs in orbit around the earth. In addition, the measurement, control and data transmission of the space payload uses the aerospace-specific encryption protocol, which makes the data very hard to be decrypted. Our payload also adopts the hardware architecture dedicated for the aerospace industry, increasing the difficulty of cracking due to the vast difference compared to terrestrial hardware. Furthermore, the private keys are only generated once after our bitcoin multisig payload is installed in the ISS. In addition, these private keys are stored in the bitcoin multisig payload which cannot be accessed by either SpaceChain or any other terrestrial parties. These processes make the transaction much more secure because it creates additional barriers for an attacker to overcome.
The SpaceChain bitcoin multisig payload facilitates transactions and is not a full archival node meant to store all the transactions starting from the Bitcoin genesis block. This is a demonstration of cold storage multisig capabilities being extended to the low Earth orbit, the ISS and the new space economy.