What does it do?
When we speak of wallets, in fact we speak mainly of a key store. On the one hand, wallets contain your collection of private keys used to sign your cryptocurrencies transactions. On the other hand, transactions are sent to public keys used a kind of destination address. As an additional service, several wallets display all transactions attached to these public keys.
Blockchains like Bitcoin do not behave like programmable blockchains, for example, like Ethereum. Ethereum transactions have a from attribute indicating the address sender. In the case of Bitcoin there is none. To uniquely identify the source of funds, the Interblockchain key store, supporting the Hierarchical Deterministic Key convention, allocates a key for each transaction. This key is part of a hierarchy of keys which can all be signed with a single private key. This way, it becomes possible to determine if funds from a particular transaction is effectively confirmed
In the illustration above, the ledger sends a request to the keyStore service through a REST API, more particularly, an HTTP GET as illustrated below. The service returns an address uniquely associated to a particular user (user ID) for a particular blockchain. A user ID can be associated to several blockchains.
The key store is part of SaaS (Software as a Service) interblockchain services. Users need to obtain an application ID to use blockchain services.