Minotaur-Mithril PoC follow-up

[jpraynaud]

Why

The Minotaur project team has worked on a prototype of implementation of the Mithril client in their developments.
Their need is to certify UTxOs from some pre-specified address. In order to do so, they have used the existing Cardano Transaction certification. The current implementation was fine for a Proof of Concept, but some new features would be needed in order to be ready for production use.

What

New features needed for production usage:

• Enhanced certification of the transactions with combination of (tx_hash, block_hash, block_number) instead of only the tx_hash.
• Certification as close as possible from the tip of the chain (and provide finality probability depending on depth from tip of the chain when snapshot is created).
• Provide a way to download the certificate chain with the client library.
• Provide a way to verify a certificate chain previously downloaded with the client library.