WalletSSI (RFC-014)

Document Maintainers: Andi Gabriel Tan 2024. List of other contributors in Annex. 1.

Copyright: MIT license

Copyright © 2018-2024 Axiologic Research and Contributors.

This document is licensed under MIT license.


The vision we are working on is getting bigger and, as time goes on, we improve it and promote it. This involves a change in the Internet and the idea of a web browser, or rather a change in a concept that arises, where instead of browsing the sites and interacting with different servers, there is a synergy between a browser and a wallet so that the user can use different functionalities or applications in a Self-Sovereign way. There is a way in which, from a browser, we can explore various self-sovereign applications, but make sure they do not start extracting data and sending it to servers or start spying or profiling users and so on.

Currently, we have the technology to build SSApps and create this browser expansion. We mention browsers because we use certain technologies when we embed these SSApps into Wallets. The code can be generalized with other technologies, and so can the implementation. The important thing is that the new browser, capable of running these SSApps, must behave like a wallet, it must take care of personal keys and it must be able to mediate the user’s interaction with cryptography. It must also ensure a high level of key management quality.


Wallets can be used to store different kinds of KeySSIs and personal user data. WalletSSIs use the same principles as ArraySSIs, but are used to identify and manage wallets. It is expected to have the credentials necessary to access the wallet in the array (like a username and password), but we could theoretically add more credentials, such as an answer to a question.

Figure 1: ConstSSI

Similar to ArraySSI and PasswordSSI, WalletSSI can be used to derive a ConstSSI, which provides access to a DSU.

SubType Description
wallet A WalletSSI is basically an ArraySSI that is used for wallet identification.

1. Type-specific and control substring

The identifier contains the subtype and the domain. That is very important for finding the correct brick storage and anchoring services associated with the keySSI and the DSU. After these two attributes, we have the type-specific and the control substring. The table below presents the content of these attributes.

Type Type Specific substring Control substring
wallet encoded(KDF(arrayOfCredentials)) none

2. Specific functions for WalletSSIs

(Common functions for all KeySSIs are available here)

Function walletSSI.initialize(dlDomain, array, vn, hint)

Description: Initialize a WalletSSI with your own parameters.

Name Type Value Description
dlDomain string *required The blockchain domain wanted to be used.
array string *required The array will be used in the initialization to get the final specific string of your WalletSSI.
vn (optional) string   The version number of the SeedSSI you want to use.
Default value: “v0”.
hint (optional) string   Optional information for the keySSI resolver.
Default value: undefined

Function walletSSI.derive()

Description: Derive your WalletSSI and return a constSSI. The constSSI will conserve all parameters from the ArraySSI, except for a control substring that will be added. The specific substring of the ConstSSI will be the same as the one calculated during the initialization of the WalletSSI using the array of inputs. It is then possible to create and load a DSU using the ConstSSI.


SubType Description
constSSI object A constSSI object is returned.

Function walletSSI.getEncryptionKey()

Description: Get the encryption key associated with the WalletSSI.


SubType Description
string The encryption key.

Function walletSSI.getTypeName()



SubType Description
SSITypes.WALLET_SSI A string representing the type of the SSI.

Function walletSSI.createAnchorValue(brickMapHash, previousAnchorValue, callback)


Name Type Value Description
callback function    

Callback parameters

Name Type Response example
err Error Object  

Description: Contains a message and the error. / The anchor value that was just created.

3. Cryptographic algorithms used by WalletSSIs (advanced)

In this paragraph, we present the algorithms that WalletSSI used. These algorithms can differ according to the type of KeySSI used and its version number. Most of the functions use the NodeJS crypto library.

Name Type Algorithms -
Default keyDerivation crypto.deriveKey(‘aes-256-gcm’, password, iterations)
Default encryptionKeyGeneration Generate a random encryption key compatible with the aes-256-gcm algorithm.
Default encoding Base58 encoding.
Default decoding Base58 decoding.


  1. Axiologic Research: New content and improvements. Original texts under PharmaLedger Association and Novartis funding. MIT licensed content accordingly with the contracts. Publish and maintain the www.opendsu.org site.

  2. PharmaLedger Project: Review, feedback, observations, new content, and corrections MIT licensed accordingly with the consortium agreements.

  3. PrivateSky Research Project: MIT licensed content accordingly with the contracts. https://profs.info.uaic.ro/~ads/PrivateSky/

Annex 1. Contributors

Current Editors Email
Sînică Alboaie sinica.alboaie@axiologic.net
Cosmin Ursache cosmin@axiologic.net
Teodor Lupu teodor@axiologic.net
Andi-Gabriel Țan andi@axiologic.net
Contributors Axiologic Research Email
Adrian Ganga adrian@axiologic.net
Andi-Gabriel Țan andi@axiologic.net
Cosmin Ursache cosmin@axiologic.net
Daniel Sava daniel@axiologic.net
Nicoleta Mihalache nicoleta@axiologic.net
Teodor Lupu teodor@axiologic.net
Valentin Gérard valentin@axiologic.net
PrivateSky Contributors Email
Alex Sofronie alsofronie@gmail.com (DPO)
Cosmin Ursache cos.ursache@gmail.com (UAIC)
Daniel Sava sava.dumitru.daniel@gmail.com (HVS, AQS)
Daniel Visoiu visoiu.daniel.g@gmail.com (SGiant)
Lenuța Alboaie lalboaie@gmail.com (UAIC)
Rafael Mastaleru rafael@rms.ro (RMS)
Sînică Alboaie salboaie@gmail.com (UAIC)
Vlad Balmos vlad.balmos@gmail.com (Code932)
PharmaLedger Contributors Email
Ana Balan bam@rms.ro (RMS)
Bogdan Mastahac mab@rms.ro (RMS)
Cosmin Ursache cos@rms.ro (RMS)
Rafael Mastaleru raf@rms.ro (RMS)