Self-Custody in the Stablecoin Era: a Card-Shaped Wallet
United Network explains why self-custody is key in the stablecoin era and presents its card-shaped hardware wallet: the private key lives on the chip and you sign with a tap of your phone
20min · Full recording from 09/10/2025 at Business Stage. Also available on YouTube.
The future of self-custody in the stablecoin era
Overview
How can you store your crypto securely without it being “rocket science”? In this MERGE Madrid talk, United Network reviews the rise of stablecoins and digital payments, the risks of the different custody options, and presents its proposal: a hardware wallet in the form factor of a bank card that aims to balance security, self-custody and ease of use.
What you'll learn
- From contactless to crypto cards: how digital-payment adoption reached stablecoins
- The quiet stablecoin revolution: from USDT and USDC to a market of over 200 billion
- CBDCs: why many central bank digital currency pilots did not take off
- The hacking problem: growing losses according to industry reports
- Custody options: exchanges, hot wallets and cold wallets, with their pros and cons
- The “wallet trilemma”: security, self-custody and accessibility in a single device
Session summary
Digital-payment adoption: it starts from the contactless payment experience to illustrate how a novelty becomes routine, and connects it to crypto cards that let you pay with stablecoins, though custody usually remains with the issuer.
The stablecoin revolution: it reviews their history (USDT as pioneer, then Circle/USDC working with regulators), up to a market capitalization that, according to the talk, exceeds 200 billion dollars and represents a growing share of global remittances.
CBDCs: it notes that more than 150 countries have explored central bank digital currencies, with few success stories; it cites examples such as China and the case of Nigeria, where most wallets ended up inactive.
The hacking problem: it mentions growing losses from hacks according to industry reports (billions of dollars a year), as an argument for better custody practices; these figures are those cited in the talk.
Custody options: it compares exchanges (convenient but risky, recalling cases like FTX), software hot wallets (better but vulnerable to malware) and cold or hardware wallets (more secure but often too complex for the average user).
The proposal and the “trilemma”: it presents a card-shaped hardware wallet in which the private key is generated and kept on the chip and never leaves it; you sign by tapping the card to your phone, with a PIN and automatic erasure after several failed attempts and recovery via a seed phrase, seeking a balance between security, self-custody and accessibility.
Watch the full talk
Watch the full recording on MERGE's YouTube channel, with United Network on self-custody and stablecoins.
FAQs
Why does self-custody matter with stablecoins?
Because, according to the talk, in many solutions (such as crypto cards or exchanges) custody remains with third parties rather than the user.
What is the difference between a hot wallet and a cold wallet?
In a hot wallet the private key is stored on the phone or computer; in a cold (hardware) wallet it is stored on an external device, more secure but often more complex.
What is the “wallet trilemma”?
It is the challenge of combining security, self-custody and accessibility; the talk proposes a card-shaped wallet as a balance point.
Is this investment advice?
No. This content is informational and summarizes what was presented in the talk; it does not constitute investment advice or a product recommendation. Consult a professional for your specific situation.
