# Interchain Ledger App Brief

## Current State
- The vision Cosmos has laid out of hundreds of blockchains in a single ecosystem interacting with each other is becoming a reality.
- 25 Cosmos SDK chains have IBC enabled, more chains adding IBC support every week. Cross-chain interactions are becoming more commonplace.
- Using a hardware wallet is one of the best steps a crypto user can take to harden security to prevent hacks and loss of funds.
- Existing Ledger security thought process conflicting with Cosmos.

## Problems
- Legacy issues with Amino JSON
- Current Cosmos app only supports signing Amino JSON
- Proto signing application will need to be released
- Signmode textual ADR([link](https://github.com/cosmos/cosmos-sdk/pull/10701/files)) led by Regen Network team
- Is signmode textual acceptable for Ledger's standard?
- What are some potential concerns?
- Confusion for web app developers around two different signing methods on Cosmos, with various levels for compatibility across SDK versions and Ledger support
- Lack of standardization on cointype
- **Uses Cosmos Hub cointype**: Cosmos Hub, Osmosis, Regen Network, Akash, etc
- **Uses own cointype, but no Ledger app**: Kava, Secret Network
- **Uses own cointype, with own Ledger app**: Terra, Desmos, Persistence
- Barrier to entry for good security practice (using a hardware wallet)
- Unsustainable to expect users to install 20 Ledger apps to interact with the Cosmos application-specific blockchains
- Unclear definition of what the 'Cosmos app' is
- Is it the Hub? or the entire ecosystem?
- Lack of composability vs lack of privacy
- **Composability**
- I don't need to install a 'MakerDAO' app to interact with the MakerDAO smart contracts, why do I need a 'Alice Chain' app to interact with the Alice Chain app?
- **Privacy**
- I didn't realize that using a common cointype across Cosmos blockchains meant someone could link my addresses across Cosmos blockchains
- If solutions are proposed to above problems, will they apply to other hardware wallets?

## Discussion points
- Implication of 'one chain, one BIP44 cointype' to prevent replay attacks
- 'What is a chain?'
- How does Cosmos prevent replay attacks, and is it enough?
- What is the role of the wallet?
- Keplr's perspective
- Private key management (not storage)
- Show content of transaction (ETH contract signing?)
- Application interface
- Ledger Live support

## Goals and Objectives
- Coming to a common acceptable specification with considerations for good practical security and interchain UX across various stakeholders
- Signal standardization across Cosmos ecosystem chains (opt-in basis)
- Ship interchain-focused Ledger app
- Document thought process, decisions and share conclusion to guide future decision making

## Examples / User stories
- **Agoric** is launching with their own Ledger app because the current Cosmos app can't provide signing for offer-safety. But if 'sign mode textual' was available, Agoric would be happy to use a common 'Cosmos' Ledger app
- **Desmos** has launched a new chain with an airdrop that token holders need to prove ownership of a foreign chain address. The process was confusing for users as Keplr wallet only supports the Cosmos Ledger app, but no the Desmos Ledger app
- Users of **Secret Network** that imported their previously extension-wallet-managed mnemonic to their Ledger Nano S (bad security practice?) has realized that they can't access their existing funds. After research and help from the community, I realized I need to unstake all my tokens then transfer my assets to my Ledger address.

## Stakeholders
Would like this list to include the least amount of stakeholders as possible to efficiently drive early-stage progress. Thoughts?
- Interchain Foundation
- Interchain Foundation funding various core entities contributing to the research, development, operations, and maintenance of various products in the Cosmos ecosystem
- Ledger
- The largest and the only hardware wallet that supports signing for Cosmos SDK blockchains
- Regen Network
- Primary developer/maintainer of the Cosmos SDK
- ZondaX
- Developer of the Cosmos Ledger app
- Confio
- Developer of CosmJS singing library
- Chainapsis / Keplr
- Developer of Cosmos wallet
- Cosmostation
- Developer of Cosmos wallet