Identity Backup and Recovery Library
Go-backup is a backup and retrieval library to demonstrate the how we could integrate this functionality into iden3's identity wallet. This first version includes the basic functionality to:
- Generate a random finite field element that will be used as a Key. Finite field is configurable.
- Generate (N,k) Shares of this key using the specified secret sharing algorithm. For now, only Shamir's Secret sharing is implemented, where N is the maximum number of shares and k is the minimum number of shares required to regenerate the key.
- Generate the Key back using k Shares retrieved from Custodians.
- Encode shares into some bytestream format that can be later recovered.
- Generate a QR code with the Share bytestream.
- Decode the QR containing the Shares
- Encode an arbitrary number of data structures that we want to store in a backup file so that they can be later recovered
- Generate an Encryption key using some Key Derivation Scheme. For now, only PBKDF2 or direct Key methods are implemented, but they can be easily expanded
- Encrypt and decrypt data structures adding enough information in a header so that they can be later decrypted. Also, we allow to include information with no encrpytion that can be recovered without a Key.
go-backup includes 4 packages:
- ff : Finite Field Arithmetic Library based on goff (https://github.com/ConsenSys/goff). It defines an interface whose methods are implemented by different elements created with goff.
- shamir : Shamir's Secret Sharing Library
- filecrypt : Encryption Library
- backuplib : mobile friendly wrapper for ff, secret and filecrypt libraries