TaskManager

On-chain entry point for CoFHE integration that initiates FHE operations, generates unique handles, and verifies decrypt result signatures

Aspect	Description
Type	Contract deployed on the destination blockchain
Function	Acts as the on-chain entry point for CoFHE integration
Responsibilities	• Initiates FHE operations by serving as the on-chain entry point. The dApp contract calls the FHE.sol library which triggers the TaskManager contract to submit a new encrypted computation task. • Generates unique handles that act as references to the results of FHE operations. These results are computed asynchronously off-chain. • Emits structured events containing the unique handle of the ciphertext, operation type, and other required metadata. • Verifies ECDSA signatures on client-published decrypt results and stores them on-chain.
Deployment	A separate Task Manager Contract is deployed for each supported destination chain, enabling chain-specific integrations

Decrypt Result Signature Verification

The TaskManager supports permissionless publishing of decrypt results. Anyone holding a valid ECDSA signature from the Threshold Network’s Dispatcher can publish a decrypt result on-chain. The TaskManager verifies the signature before storing the result.

Key State

Variable	Description
decryptResultSigner	Address of the authorized Threshold Network signer. Set to address(0) to skip verification (debug mode).

Functions

Function	Description
publishDecryptResult(ctHash, result, signature)	Verify signature and store the decrypt result on-chain. Emits DecryptionResult.
publishDecryptResultBatch(ctHashes[], results[], signatures[])	Batch publish multiple results in one transaction for gas efficiency.
verifyDecryptResult(ctHash, result, signature)	Verify a signature without publishing (view). Reverts on failure.
verifyDecryptResultSafe(ctHash, result, signature)	Verify a signature without publishing (view). Returns false on failure.
setDecryptResultSigner(address)	Admin-only. Set the authorized signer address.

Signature Message Format

The signed message is a fixed 76-byte buffer:

Field	Size	Encoding
result	32 bytes	uint256, big-endian, left-padded with zeros
enc_type	4 bytes	i32, big-endian (extracted from ctHash metadata)
chain_id	8 bytes	u64, big-endian (from block.chainid)
ct_hash	32 bytes	uint256, big-endian

The message is hashed with keccak256 and verified using OpenZeppelin’s ECDSA.tryRecover. The enc_type and chain_id are derived on-chain, binding each signature to a specific ciphertext type and chain.

Enable / Disable Switch

The TaskManager carries a global isEnabled flag that owner-only enable() / disable() calls flip. While disabled, every entry point gated by onlyIfEnabled reverts with CofheIsUnavailable — including publishDecryptResult and publishDecryptResultBatch. Read access (getDecryptResultSafe, verifyDecryptResultSafe, etc.) is not gated and continues to work.

Element	Description
isEnabled	Public bool state variable. Source of truth for whether the coprocessor accepts new operations on this chain.
onlyIfEnabled modifier	Wraps every state-changing FHE-op entry point and publishDecryptResult*. Reverts with CofheIsUnavailable when isEnabled == false.
enable()	Owner-only. Sets isEnabled = true.
disable()	Owner-only. Sets isEnabled = false — useful for emergency pause or coordinated upgrades.

Reading the flag from a client

Apps can pre-flight the switch before submitting transactions:

bool live = ITaskManager(TASK_MANAGER_ADDRESS).isEnabled();

For React apps using @cofhe/react, the useCofheEnabled hook wraps this read and reflects the result reactively — handy for showing a “CoFHE temporarily unavailable” banner without forcing users to fire a doomed transaction first.