Custody: what you control and what you depend on

Self-custody means controlling the authority needed to spend assets. It does not remove dependence on wallet software, a device, backups or transaction interfaces. Custodial services take responsibility for some of those operations while introducing account access and counterparty risk.

Separate activities with different exposure

A wallet used for unfamiliar applications need not hold long-term savings. Separating funds reduces the impact of one bad approval or compromised environment. The separation is weaker if every wallet uses a recovery phrase already exposed on the same device.

For a custodian, establish the contracting entity, withdrawal process, recovery channels and what happens if access is suspended. For self-custody, establish how recovery works after a lost device and who can access the backup. Neither arrangement is made safe by its label alone.

MASTR's Survival Guide treats custody as part of the research process because a correct investment thesis cannot undo a key compromise. The SecondFi archive also shows why software and post-incident communications remain relevant even to people who hold their own phrases.

Sources

1. MASTR: Crypto Survival Guide, four original panels
2. Ethereum: security and scam prevention

Research checked 5 September 2026. Historical cases retain the date and legal status of the cited record.