After discussion on P2MR / BIP-360 (bc1z), one open question remains: how to safely store a 32-byte SLH-DSA seed offline for cold storage / inheritance before migration exists.

Storing 64 hex in plain text is not safe - one copy, fire/theft = loss. For long-term cold storage we need the BIP-38 UX: encrypted paper backup, many copies.

Proposal: PQ-single-address-backup(SAB) v1

Goal: companion to BIP-360, not a change to BIP-360. BIP-360 defines WHAT bc1z is. This defines HOW to store its seed.

bitcoin

> *by* [**coldtest-berlin**](https://delvingbitcoin.org/u/coldtest-berlin)
>
> After discussion on P2MR / BIP-360 (bc1z), one open question remains: how to safely store a 32-byte SLH-DSA seed offline for cold storage / inheritance before migration exists.
>
> Storing 64 hex in plain text is not safe - one copy, fire/theft = loss. For long-term cold storage we need the BIP-38 UX: encrypted paper backup, many copies.
>
> Proposal: PQ-single-address-backup(SAB) v1
>
> Goal: companion to BIP-360, not a change to BIP-360. BIP-360 defines WHAT bc1z is. This defines HOW to store its seed.
>
> [**...read more at delvingbitcoin.org**](https://delvingbitcoin.org/t/pq-single-address-backup-bip-38-for-p2mr-bc1z-104-char-encrypted-backup-format/2767)