What does Stellar need for Stage 4 (Live option)?

Stage 4 needs PQ user accounts on mainnet that keep funds at rest out of reach of ECC keys (U is: testnet, hold: exposed)

Blockchain Quantum Readiness Index / Stellar

L1 · Stellar

Stellar

Accounts and validators all sign with elliptic-curve keys, and there is no official bridge. The Stellar Development Foundation has a post-quantum plan: ML-DSA verification for Soroban contracts is live on testnet since 3 November 2026, with the mainnet upgrade vote set for 23 November, native post-quantum signers are planned for 2027, and consensus is to follow through a protocol upgrade.

Stage 3Testnet

36.7/100progress index · 100% researched · 60% in scope

Last reviewed 2026-11-09

Is Stellar quantum safe?

Not yet. Stellar is at Stage 3 (Testnet) in LimeChain's Blockchain Quantum Readiness Index, with a progress score of 36.7/100. Post-quantum accounts run on a testnet, or on mainnet without keeping funds safe at rest, so users cannot rely on them yet.

Exposed (0 pts)Unknown (scored as exposed)Discussed / plannedIn development / testnetLive (hybrid or PQ)Not applicable

What Stellar needs for Stage 4: Live option

Stage 4 needs PQ user accounts on mainnet that keep funds at rest out of reach of ECC keys (U is: testnet, hold: exposed)

Caps and adjustments

cap 40: users cannot hold and spend funds under a production PQ mechanism on mainnet
cap 60: consensus PQ not even on testnet

Rosette slices

Slice	State	Points	Weight	Reason & evidence
U User keys	Testnet At rest: Exposed at rest A G... account ID is the raw Ed25519 master public key (XDR `typedef PublicKey AccountID`, StrKey type G = ED25519 public key), and additional signers are Ed25519 keys stored in the account entry, so the controlling key is on-chain from the start; rotation (master weight 0 plus a new signer) does not hide it. Flagged for review: an account whose only signers are pre-authorized-transaction hashes (or a hash(x) preimage) has no ECC key at rest, but it can only execute pre-committed transactions (hash(x) is replayable once revealed), so it is not an ordinary account and is not rated here. Sources 6 7 8 9	6/10	25	CAP-0087 (ML-DSA-44/65/87 signature verification host functions for Soroban, e.g. for custom accounts) is Implemented in protocol 30. Testnet upgraded to protocol 30 on 2026-11-03; mainnet still runs protocol 29 (Horizon, measured 2026-11-09), with the mainnet upgrade vote scheduled for 2026-11-23. Network-level transaction signatures remain Ed25519. Native PQ signers are planned for 2027. Sources 1 2 3 4 5
C Consensus	Planned	2/10	20	Stellar Core nodes identify themselves in SCP with an Ed25519 keypair (NODE_SEED is an S-prefixed strkey, which SEP-0023 defines as an ED25519 seed). SDF's Quantum Preparedness Plan commits to a protocol upgrade of SCP for network integrity, with no date. Sources 10 8 1
P Proof system	Not applicable	—	—	L1 with no validity or fraud proof system. no evidence
B Bridges & messaging	Not applicable	—	—	No canonical bridge: on/off-ramps are independent anchors issuing their own assets, and the docs list only third-party integrations (CCTP, USDT0). Sources 11
A Admin & upgrade keys	Not applicable	—	—	No privileged on-chain admin/upgrade key: network settings and protocol versions change by validator vote (SDF proposes, Tier 1 validators vote, validators apply the patch release). Sources 12 13
M Migration & recovery	Planned	2/10	15	The SDF plan is a dated migration/preparedness roadmap, but nothing is ratified on mainnet. Sources 1

Stage gates

Requirement	Status	Details & evidence
Current audit of the deployed PQ signing code (Stage 5)	Not met	not claimed
Admin timelock of at least 30 days with a PQ override (Stage 6, alternative to PQ admin keys)	Not met	not claimed
Ratified migration plan with an activation date (Stage 6)	Not met	not claimed
New accounts PQ or hybrid by default (Stage 6)	Not met	not claimed
ECC sunset enforced (Stage 7)	Not met	not claimed

PQ adoption published, not scored

There are no PQ accounts on mainnet yet. Having PQ accounts does not mean people move to them. This tracks the share of value and accounts that actually moved, over time.

Measured exposure

No on-chain probe run yet. Bitcoin, Solana, Cosmos and Substrate probes are planned.

Evidence and sources (13)

Every non-zero rating above cites at least one of these public sources.

Source: chains/stellar.json. Reproduce: python3 score.py chains/stellar.json

Building on Stellar?

LimeChain helps teams plan their post-quantum migration: what is exposed, what to change first, and the engineering to get there.

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Open, repeatable scoring. Non-zero ratings need public evidence; missing evidence means unknown. Methodology v0.4 · mechanism registry 2026-10-13.