[ANN] JETSAM (JTM) | PoW L1 | O(1) Historical Verification | 21M Cap | Zero Premine
What is Jetsam?JETSAM is an independent proof-of-work Layer 1 network based on recursive history proofs.
A Jetsam node does not replay the complete block history from genesis in order to authenticate the present. It authenticates the current state commitment, verifies one recursive proof representing prior valid history, and checks a bounded recent suffix of
8 blocks.
This makes
historical verification independent of total chain age. It does not make the chain state-free: node storage still depends on the live state, alongside the current head proof and bounded recent-block window. In other words, Jetsam is designed to be history-bounded, not to claim that all node resources remain constant under arbitrary usage.
Jetsam is named after
jetsam: cargo deliberately thrown overboard to keep a ship afloat.
Lineage and Upstream ChangesJetsam is an independent Apache-2.0 fork of
ParanO(1)d.
Jetsam does not claim to have invented recursive chain proofs, the HistoryStep architecture, the FRI-Binius proving stack, or the underlying soundness argument. Those parts originate from the upstream project and the research it builds upon.
Jetsam is a separate network. Its peers, proof-of-work, consensus rules, monetary policy, addresses, and chain data are incompatible with ParanO(1)d.
Jetsam keeps from ParanO(1)d:- The recursive HistoryStep proof architecture.
- The historical-proof soundness approach.
- The FRI-Binius proving stack.
- The transparent UTXO model: transaction amounts and owners are public.
Jetsam changes:- A height-based emission schedule with a 21,000,000 JTM hard cap.
- Zero-premine genesis and an emission schedule beginning at height 1.
- A capped, consensus-enforced development fund limited to the first two years.
- Parent-anchored difficulty to address timestamp-grinding behavior in the upstream rule set.
- A 90-second protocol block target, selected above the stated proving-latency range.
- TowerHash proof of work, with Jetsam-specific domain tags, constants, sponge schedule, and nonce placement.
- Encrypted wallet keys at rest.
Protocol Constants| Network | JETSAM mainnet |
| Native coin | JTM |
| Consensus | Proof of Work — TowerHash |
| Maximum supply | 21,000,000 JTM |
| Premine | 0 — genesis block carries no coinbase |
| Block interval | 90 seconds |
| Recent verification window | 8 blocks |
| Confirmation target | 8 blocks; approximately 12 minutes at the 90-second target interval |
| Historical verification model | Live state + bounded recent window + current recursive proof |
| Address format | bech32m, prefix j1… |
| License lineage | Apache-2.0 derivative, with upstream changes documented |
Constant-Size Historical VerificationEvery Jetsam block contains a recursive
HistoryStep proof.
The proof in block
n verifies that the terminal commitment of proof
n−1 was valid. That prior proof already attests to the preceding proof, continuing recursively to genesis. A node can therefore validate the current head proof without re-executing the entire historical chain.
A new node performs three bounded operations:
- Authenticates the current state against the head commitment.
- Verifies one recursive proof representing all prior chain history.
- Verifies the most recent 8-block suffix.
The intended result is that joining at block height 3,000,000 requires the same historical-verification work as joining near the beginning of the network, apart from the live state and fixed recent-block window.
State ModelJetsam uses a fixed accumulator of state slots.
When a coin output is spent, its slot is erased and can be reused by a later transaction. The protocol therefore aims to avoid an unbounded set of spent outputs, nullifiers, or historical UTXOs. State is intended to scale with live coins rather than every transaction ever executed.
- Spent outputs are erased from their slot.
- Empty slots are reusable by future outputs.
- Net-new state growth is priced through a consensus burn.
- Old validated block bodies can be jettisoned after their validity is carried by the recursive proof.
Emission ScheduleJTM has a hard cap of
21,000,000 coins, enforced by the consensus emission schedule.
- Genesis block: no coinbase and no premine.
- First block reward: 50 JTM at height 1.
- Seven scheduled halvings by block height.
- Final coinbase subsidy: 0.78125 JTM during the final reward era.
- Subsidy becomes exactly zero at height 3,467,664, estimated at approximately 9.9 years after launch.
- After the subsidy ends, miners are compensated through transaction fees.
The published halving boundaries are:
28,800
172,800
831,800
1,490,800
2,149,800
2,808,800
3,467,800
The final reward era is trimmed so that total issuance reaches exactly 21,000,000 JTM rather than approximating the cap.
Development FundThe protocol includes a limited development fund:
- 10% of the block subsidy during the first two years only.
- Total allocation: 1,163,996 JTM.
- Share of maximum supply: 5.54%.
- Distribution: a consensus-enforced daily batch visible on-chain.
- The development-fund issuance ends after the two-year period.
MiningJetsam uses
TowerHash, a proof-of-work construction based on a sponge over the Poseidon2b permutation using a binary tower field, GF(2¹²⁸).
According to the project specification:
- TowerHash uses XOR and carry-less multiplication rather than modular arithmetic.
- The nonce is placed in lane 0 to prevent midstate precomputation, so each mining attempt requires all 8 permutations.
- Difficulty is anchored to the parent block to remove a timestamp-grinding vector present in the upstream design.
- The protocol target interval is 90 seconds. Observed block intervals may vary, particularly during early network operation and difficulty adjustment.
- CPU mining is included directly in the node software through
.[/li]
- No public GPU miner is currently available.
- The mining work protocol is public JSON-RPC, allowing independent miner and pool implementations.
Important: As with every proof-of-work network, miners should independently review the implementation, consensus rules, hashrate conditions, software releases, and operational risks before mining.
Spend Authorization and CryptographyJetsam does not use an elliptic-curve signature scheme for spending. Spending is authorized through a zero-knowledge proof of a hash preimage, integrated into the block’s recursive proof.
The project describes this design as post-quantum by construction because it avoids elliptic-curve signatures. This is a design claim; users, miners, and researchers should independently evaluate the cryptographic assumptions and implementation.
Published components and references include:
- Poseidon2b binary-field permutation.
- Binius binary-field proof framework.
- FRI low-degree testing.
- Ligerito polynomial commitment.
- The project cites a proven 127-bit soundness bound inherited from its upstream base. The design target is in the interval [127, 128) bits; it is not presented as a completed independent 128-bit proof for Jetsam.
Mainnet StatusThe JETSAM website states that mainnet is live and producing blocks under the published emission schedule.
The protocol, source code, and mining interface are public. Additional independent implementations and mining software may be developed in the future; only releases published through official project channels should be treated as official.
- Premine: None
- Official price: No price quoted by the project
- Official holder count: No holder count advertised by the project
- Live network data: Check the official explorer for chain height, difficulty, supply, and blocks.
Official Links
JETSAM — Proof-of-Work L1 with recursive history proofs, bounded historical verification, a 21,000,000 JTM hard cap, and zero premine.
