Version compatibility

Which cryptographic and contract versions line up across a protocol release — and how the SDK picks the right tfhe.wasm version for a given chain. This page is the source of truth for the (protocol, PubKey/CRS, TFHE, KMS) matrix.

For where the SDK runs (browser, Node, Edge, SSR/CSR) rather than which versions are compatible, see Runtime compatibility.

Source repositories

• KMS: github.com/zama-ai/kms
• tfhe-rs: github.com/zama-ai/tfhe-rs

The core limitation

There is no on-chain or Relayer-side signal that tells the SDK the minimum tfhe.wasm version required to deserialize a given PubKey/CRS pair, and the format is not forward-compatible across minor versions:

• [email protected] cannot parse a PubKey/CRS produced by [email protected].

How the SDK picks a tfhe.wasm version

Lacking a direct signal, the SDK derives the right tfhe.wasm version from a protocol context:

1. Read ACL.version on the host chain and map it to a protocol version.
2. Resolve the PubKey/CRS version from what this SDK knows at the time it is written:
   • for known public Relayers, use the PubKey/CRS version they are known to serve at SDK release time;
   • otherwise, use the PubKey/CRS version expected when fresh key material is generated for that protocol line.
3. Map (protocol version, PubKey/CRS version) to a wasm version:
   • Protocol < v0.13.0 with PubKey/CRS < v1.6.0 → [email protected]
   • Protocol ≥ v0.13.0 with PubKey/CRS < v1.6.0 → [email protected] by default, while v1.5.3 remains compatible for the current legacy public PubKey/CRS.
   • Protocol ≥ v0.13.0 with PubKey/CRS ≥ v1.6.0 → [email protected]

The PubKey/CRS part is a release-time snapshot, not a future-proof signal. After the SDK is published, key rotation or CRS removal can change the material served by a Relayer. The SDK cannot guess those future changes without a direct on-chain or Relayer-side version signal.

The protocol-version part works as long as every protocol release bumps at least one host-contract version.

{% hint style="info" %} A future protocol version could expose this directly via view functions on InputVerifier.sol / KMSVerifier.sol or ProtocolConfig.sol, removing the need for the heuristic above. {% endhint %}

KMS ↔ tfhe-rs

KMS releases pin an exact tfhe-rs crate version via tfhe = "=X.Y.Z" in the workspace Cargo.toml.

KMS version	tfhe-rs crate	Notes
0.12.4 – 0.12.7	1.4.0-alpha.3	initial line, prerelease alpha
0.13.0 – 0.13.3	1.5.1	tfhe minor bump (1.4 → 1.5)
0.13.10	1.5.4	tfhe patch bump within 1.5.x
0.13.20-0	1.6.1	tfhe minor bump (1.5 → 1.6)

Deployed chains

KMS 0.12.7 generated the PubKey/CRS in December 2025.

Chain	Protocol	PubKey/CRS
Mainnet	0.11.0	1.4.0-alpha.3
Testnet	0.13.0	1.4.0-alpha.3
Devnet	0.13.0	1.4.0-alpha.3
Polygon-Amoy (Devnet)	0.13.0	1.4.0-alpha.3
Hoodi	?	?

Contract and component versions

On-chain contracts

Protocol	ACL	FHEVMExecutor	KMSVerifier	InputVerifier	HCULimit	ProtocolConfig	PauserSet
0.10.0	0.2.0	0.1.0	0.1.0	0.2.0	0.1.0	-	0.1.0
0.11.0	0.2.0	0.2.0	0.1.0	0.2.0	0.1.0	-	0.1.0
0.12.0	0.3.0	0.3.0	0.2.0	0.2.0	0.2.0	-	0.1.0
0.13.0	0.4.0	0.4.0	0.3.0	0.2.0	0.3.0	0.1.0	0.1.0
0.14.0	0.5.0	0.5.0	0.4.0	0.2.0	0.4.0	0.2.0	0.1.0
0.15.0	?	?	?	?	?	?	?

Off-chain components

Protocol	TFHE	KMS	Extra data
0.10.0	1.4.0-alpha.3	0.12.4	v0
0.11.0	1.5.1	0.13.3	v0
0.12.0	1.5.4	0.13.10	v1
0.13.0	1.6.1	0.13.20-0	v1
0.14.0	1.6.2	0.13.20-0	v2
0.15.0	?	?	?

PubKey/CRS versions on deployed chains and TFHE readability

Chain	Protocol	PubKey/CRS (TFHE)	TFHE 1.5.3	TFHE 1.6.2
Mainnet	0.11.0	1.4.0-alpha.3	✅	❌
Testnet	0.13.0	1.4.0-alpha.3	✅	✅
Devnet	0.13.0	1.4.0-alpha.3	✅	✅

Localstack

Protocol	PubKey/CRS (TFHE)	Readable by TFHE 1.5.3	Readable by TFHE 1.6.2
0.11.0	1.5.1	✅	✅
0.12.0	1.5.4	✅	✅
0.13.0	1.6.2	❌	✅
0.14.0	1.6.2	❌	?

TFHE WASM API surface

Protocol	TFHE	Types	Functions
v0.11.0
v0.12.0
v0.13.0
v0.14.0
v1.5.3
v1.6.2	CompactCiphertextList.builder
CompactCiphertextListBuilder.push_boolean
CompactCiphertextListBuilder.push_u8
CompactCiphertextListBuilder.push_u16
CompactCiphertextListBuilder.push_u32
CompactCiphertextListBuilder.push_u64
CompactCiphertextListBuilder.push_u128
CompactCiphertextListBuilder.push_u160
CompactCiphertextListBuilder.push_u256
CompactCiphertextListBuilder.build_with_proof_packed
CompactCiphertextListBuilder.free
CompactPkeCrs.safe_serialize
CompactPkeCrs.safe_deserialize
ProvenCompactCiphertextList.safe_serialize
ProvenCompactCiphertextList.safe_deserialize
ProvenCompactCiphertextList.free
ProvenCompactCiphertextList.len
ProvenCompactCiphertextList.get_kind_of
TfheCompactPublicKey.safe_serialize
TfheCompactPublicKey.safe_deserialize
ZkComputeLoad	init_panic_hook
initThreadPool
setWorkerUrlConfig
getWasmInfo

KMS WASM API surface

Protocol	KMS	Types	Functions
v0.11.0
v0.12.0
v0.13.0
v0.14.0
v0.13.x
v0.14.0	Client
PrivateEncKeyMlKem512
PublicEncKeyMlKem512
ServerIdAddr
TypedPlaintext	new_client
new_server_id_addr
ml_kem_pke_keygen
ml_kem_pke_get_pk
ml_kem_pke_pk_to_u8vec
ml_kem_pke_sk_to_u8vec
u8vec_to_ml_kem_pke_sk
process_user_decryption_resp_from_js

Related

• Runtime compatibility — supported runtimes and rendering environments.
• Chains — the per-chain contract addresses these versions map to.
• Runtime configuration — pinning module versions via moduleVersions.