Chain profile
Signs transactions and blocks with 4096-bit RSA-PSS keys by default, or with ECDSA on secp256k1 since the 2.9 hard fork, and has published no post-quantum plan, proposal or research programme for either.
No. Arweave is a permanent data storage chain with its own proof-of-access mining consensus, and its wallets sign with one of two schemes that a sufficiently large quantum computer running Shor's algorithm would break. The default, and the scheme the original wallets use, is RSA-PSS with 4096-bit keys and SHA-256; since the 2.9 hard fork at block 1,602,350 on 3 February 2025, wallets and miners may also use ECDSA on secp256k1. An Arweave address is the SHA-256 hash of the public key, but every RSA transaction carries the sender's full public key in its owner field, and an ECDSA public key is recovered from the signature, so any wallet that has sent a transaction has published its key. Miners sign blocks with the same kinds of wallet key, and each block records the miner's public key. We found nothing on post-quantum signatures in the node's code, release notes, documentation, yellow paper or lightpaper, or from the Arweave team. The node's source contains Ed25519 key handling, but the transaction rules accept only RSA and ECDSA, and Ed25519 would not be post-quantum either.
Where we are making a judgement call Three judgement calls. The first is exposure. RSA transactions publish the full public key in their owner field, storing data needs a signed transaction, and every block records its miner's key, which argues for a 1; a reader who scores it so would give a Hardy Score of 7.5 rather than 8.5. We hold it at 2, the score for account-model key-hash chains, because receive-only wallets do keep their keys hidden and no measured share of exposed AR has been published. The second is migration. The 2.9 fork added a second signature type without disturbing existing wallets, which is the path a post-quantum type would take, and we credit that record with a 2; at 1 the Hardy Score would be 7.0. The third is the treatment of RSA. Breaking 4096-bit RSA is generally estimated to need a larger quantum computer than breaking 256-bit elliptic curves, and a reader might rate Arweave's default wallets as later to fall. Shor's algorithm breaks both, and the rubric scores whether a scheme is quantum-vulnerable, not how soon, so no score changes on this reading. Separately, our finding is that we could not locate a published post-quantum position from the Arweave team, not that we have confirmed none exists.
RSA-PSS with 4096-bit keys and SHA-256 by default for wallets and block signing; ECDSA on secp256k1 accepted for wallets and miners since the 2.9 hard fork
None selected or proposed
None adopted
Tier 5: Exposed. The signatures securing funds on mainnet today are quantum-vulnerable, and no public post-quantum plan, proposal or research programme addressing them could be found.
A role not listed is not evidenced either way. Every scheme, and which other chains share it, is in the cryptography registry.
| No. | Dimension | Score | Weight | Contribution |
|---|---|---|---|---|
| 1 | Signature scheme | 0 | 30% | 0.0 |
| 2 | Deployment stage | 1 | 25% | 2.5 |
| 3 | NIST alignment | 0 | 15% | 0.0 |
| 4 | Migration path | 2 | 15% | 3.0 |
| 5 | Exposure | 2 | 10% | 2.0 |
| 6 | Verification | 2 | 5% | 1.0 |
| Hardy Score | 8.5 | |||
Band 0: Classical signatures only on mainnet, with nothing post-quantum protecting live funds. Short-lived devnets and one-off benchmarks sit here: they demonstrate research rather than something a user can hold keys on.
The node accepts two transaction signature types: RSA-PSS with 4096-bit keys and public exponent 65537, the default, and ECDSA on secp256k1, accepted on format 2 transactions from the 2.9 fork height. Shor's algorithm breaks both, and nothing post-quantum protects AR on mainnet. source
Band 1: Tier 5: Exposed.
Tier 5: Exposed. The signatures securing AR are quantum-vulnerable, and no post-quantum proposal, plan or research programme from the Arweave team or from the Digital History Association, which prepared the 2.9.1 and 2.9.6 node releases, was found: none in the node repository's code, issues or release notes, the developer documentation, the yellow paper or the lightpaper. Work by projects built on Arweave, such as AO, is not work on Arweave's own signatures. source
Band 0 to 2: No post-quantum scheme named for the chain’s fund-protecting signatures, or a proprietary scheme with no public cryptanalysis.
No post-quantum scheme has been named for Arweave's transaction or block signatures by anyone with authority over the chain, so there is nothing to align with a NIST standard. The one signature type added in recent years, ECDSA on secp256k1, is classical. source
Placement in the band The floor of the band rather than a 1 or a 2: no scheme has been named for Arweave's signatures at all, not even as an example or candidate, so there is no partial alignment to credit.
Band 0 to 2: No agreed migration path, or the proposals on the table would strand or freeze holder funds.
No migration plan exists. Arweave does have working machinery a migration could use: transactions carry a signature type, and the 2.9 hard fork used it to add ECDSA keys beside RSA without disturbing existing wallets, while the 2.9.6 fork of September 2026 retired format 1 transactions. There is no in-place key rotation, since the documentation says there is no account delegation mechanism, so a holder would move AR to a new address. source
Placement in the band The top of the band rather than a 0 or a 1: Arweave has added a signature scheme through a coordinated hard fork and retired an old transaction format through another, which is the route a post-quantum key type would take. Not a 3, because no one with authority over Arweave has acknowledged quantum migration as a problem.
Band 0 to 2: Public keys are exposed for effectively all accounts, or a large, measured share of total supply sits in exposed addresses.
An Arweave address is the SHA-256 hash of the public key, so a wallet that has only received AR keeps its key off the chain. Sending reveals it: the owner field of an RSA transaction is the full RSA modulus of the sending wallet, and an ECDSA key is recovered from the transaction's signature. Uploading data is itself a signed transaction, and every block records the miner's public key. source
Placement in the band The top of the band rather than a 1: hashed addresses do keep the keys of receive-only wallets hidden. Not a 3, because any wallet that has paid for storage or sent AR has published its key, and no measurement of the exposed share of supply has been published.
Band 0 to 2: No post-quantum component exists, or the claims rest on marketing.
No post-quantum component exists for Arweave: no code, specification or testnet implementation for its signatures was found. The node is open source, but under v1.8 the openness of the classical code earns nothing here. source
Placement in the band The top of the band rather than a 0 or a 1: there is no post-quantum component to verify, but nothing about Arweave is marketed as quantum-safe by the project, so its position does not rest on marketing.
The deployment dimension is not a separate judgement. It is Tier 5 expressed as a number. See the tier mapping.
The 9 chains Arweave sits among, out of 80 rated. The last column is the gap in Hardy points from Arweave.
| Rank | Chain | Tier | Hardy | vs AR |
|---|---|---|---|---|
| 49 | Dogecoin | 5: Exposed | 9.0 | +0.5 |
| 50 | 0G | 5: Exposed | 8.5 | level |
| 51 | AIOZ Network | 5: Exposed | 8.5 | level |
| 52 | Akash Network | 5: Exposed | 8.5 | level |
| 53 | Arweave this chain | 5: Exposed | 8.5 | |
| 54 | Avalanche | 5: Exposed | 8.5 | level |
| 55 | Bitcoin SV | 5: Exposed | 8.5 | level |
| 56 | Celestia | 5: Exposed | 8.5 | level |
| 57 | Chiliz Chain | 5: Exposed | 8.5 | level |
The 2.9 hard fork activates at block 1,602,350, adding ECDSA secp256k1 keys for transactions and block signing beside RSA, which remains the default. Announced in the 2.9.1 release notes; neither scheme is post-quantum. source
The 2.9.6 soft fork activates at block 2,000,000 and ends acceptance of format 1 transactions. The release notes mention no change to signature schemes. source
No proposal, specification, implementation or timeline for post-quantum signatures on Arweave was found. source
No stated policy
No release note, documentation page or statement from the Arweave team addresses AR in wallets that never move to post-quantum keys, since no post-quantum key type has been proposed.
As of 22 October 2026. source Published beside the score, not in it. Every chain's stance is compared on the commitments page.
Exposure measures how much of the chain's value already sits behind a public key that an attacker can record today and break later. This is the part of the threat that a future upgrade cannot undo.
Arweave addresses are the SHA-256 hash of the wallet's public key, so a wallet that has only ever received AR has not published its key. The first transaction publishes it permanently: for an RSA wallet the owner field carries the full 4096-bit modulus, and for an ECDSA wallet the protocol recovers the key from the signature, which anyone can do. On Arweave paying to store data is a signed transaction, so every wallet that has uploaded anything, as well as every wallet that has sent AR, has a public key on the permanent record. Miners sign blocks with wallet keys, and each block records the miner's public key. No measurement of the share of AR behind revealed keys has been published, so the score rests on the address model.
What this rating means for you
Arweave runs quantum-vulnerable signatures with no published post-quantum plan that we could find. Nothing here is urgent today, and there is also nothing scheduled to change it.
Editorial guidance from the Hardy Index.
We will email you the day this rating moves, with the changelog note that explains why. Nothing else, and nothing in between.
No. Arweave wallets sign with RSA-PSS or with ECDSA on secp256k1, and miners sign blocks with the same kinds of key. A sufficiently large quantum computer running Shor's algorithm would break both, and there is no post-quantum proposal or plan for Arweave.
Not in kind. Shor's algorithm breaks RSA as it breaks ECDSA. A 4096-bit RSA key is generally estimated to need a larger quantum computer than a 256-bit elliptic-curve key, which may buy time, but it is not post-quantum protection.
For any wallet that has sent a transaction, yes. An address is a hash of the key, but every RSA transaction carries the full public key in its owner field and an ECDSA key can be recovered from its signature. Uploading data is a transaction, so every wallet that has stored anything on Arweave has published its key.
A proposal or a public research programme from the Arweave team on post-quantum transaction or block signatures would meet the Tier 4 floor, and a published plan naming the scheme would meet Tier 3. The 2.9 hard fork showed that Arweave can add a new signature type beside the existing ones.
A rating is only true as of the day an editor last reviewed it, so both forms below carry that date and the methodology version, with the date its cited sources were last checked. If you are quoting the score, quote those too.
The Hardy Index (2026). Arweave: quantum readiness assessment. Hardy Score 8.5 of 100, Tier 5: Exposed. Methodology v1.8. Last reviewed 22 October 2026; sources checked 13 November 2026. https://hardyindex.com/chains/arweave
@misc{hardyindex_arweave_2026,
author = {{The Hardy Index}},
title = {Arweave: quantum readiness assessment},
year = {2026},
howpublished = {\url{https://hardyindex.com/chains/arweave}},
note = {Hardy Score 8.5 of 100, Tier 5: Exposed. Methodology v1.8},
urldate = {2026-11-13}
} The whole dataset is reusable under the terms on the about page. A machine-readable version of this page is at /chains/arweave.md.
This is a security-readiness assessment, not investment advice.