A new proposal made it to XRP Ledger’s developer channels, and this one is trying to turn the quantum threat debate into something actionable: a protocol-level option that lets accounts rotate a “single-use” signing key on every transaction, so the key is automatically discarded after one successful use.
Filed as XRPL Amendment idea #420, the draft comes from developer Ed Hennis and credits inspiration from Nik Bougalis and David Schwartz. Worth to note, the concept is not a new encryption scheme. Instead, it adds a new field — proposed names include SingleUseKey and QuantumSafeKey.
The logic is simple: if quantum-capable key breaking ever becomes practical, attackers would still need time after a public key is exposed. The proposal assumes that time would exceed XRP Ledger’s fast validation cycle, limiting the chance that an attacker could break seeing a key once and then replace a transaction fast enough to win on-ledger.
More details for XRP
In the suggested user flow, an account keeps a recoverable Regular Key stored safely, sets a SingleUseKey, then disables the Master Key after setup. From then on, each transaction is signed with the current single-use key while the next one is being set, creating a rolling chain that reduces how often keys are reused and how much they are exposed.
The draft also points out some risks that could come up in practice. For example, tickets can lead to ordering problems, multisigning adds extra work to implement, and user error is still user error — if you reuse a key or mishandle sequencing, the network cannot protect you.
Even so, as quantum anxiety is becoming more common in the crypto markets, the proposal gives XRPL a real way to deal with the issue. It can be used as an optional security upgrade.
