TECHNOLOGY

ConvergenceX
Consensus Engine

A deterministic, CPU-oriented, security-first consensus engine combining gradient-descent proof-of-work, per-block adaptive difficulty, and a real-time stability overlay. Designed for predictable issuance, controlled growth, and resistance to chaotic retarget behavior.

CONSENSUS | Integer-only arithmetic · Zero floating point · Deterministic across all nodes
OVERVIEW

Architecture Pipeline

Layer 01
ConvergenceX PoW
Gradient-descent work
+ stability basin proof
Layer 02
cASERT bitsQ
Per-block difficulty
Q16.16 adjustment
Layer 03
cASERT Equalizer
Structural correction
Adaptive mode control
Layer 04
SOSTCompact
Q16.16 difficulty
encoding (nBits)
Layer 05
MTP Validation
Median Time Past
timestamp discipline
The consensus stack is vertically integrated: ConvergenceX produces the proof-of-work, cASERT controls difficulty via three layers — bitsQ primary controller adjusts every block in continuous Q16.16 log-space, the equalizer applies structural correction via ConvergenceX stability profiles, and anti-stall ensures liveness — while MTP anchors all timing decisions to validated chain history. Every layer is integer-only and bit-for-bit reproducible across all implementations.
PROOF OF WORK

ConvergenceX PoW

convergencex_attempt()
CONSENSUS-CRITICAL

Instead of brute-force hash collision, ConvergenceX requires miners to produce verifiable convergence certificates using Transcript V2. Each attempt solves a tip-bound linear system via deterministic gradient descent, mixed with memory-hard scratchpad reads, and proves the solution lies in a stable convergence basin. Transcript V2 adds segment commitments and sampled round witnesses, enabling 11-phase verification at ~0.2ms (vs ~1ms in V1). Dataset v2 (SplitMix64) and Scratchpad v2 (SHA256-indexed) are independently indexable at O(1).

// 1. Derive challenge from chain tip (anti-grinding) block_key = SHA256( prev_hash || "BLOCK_KEY" ) seed = SHA256( MAGIC || "SEED" || header_core || block_key || nonce || extra_nonce ) // 2. Derive linear system M, b from block_key (deterministic per tip) (M, b, λ) = derive_M_and_b( block_key, N=32, λ=100 ) // 3. Gradient descent with scratchpad mixing (memory-hard) for r in 1..100,000: x[i] -= ( A(x)[i] - b[i] ) >> lr_shift // gradient step x[j] ^= mix_from_scratch( scratchpad, idx ) // ASIC resistance state = SHA256( state || mix_data || round ) // state chain // 4. Verify stability basin (k perturbation probes) (is_stable, metric) = verify_convergence_stability_basin( x_final, M, b, ... ) // 5. Compute commitment commit = SHA256( MAGIC || "COMMIT" || header_core || seed || state || x || segments_root || cp_root || metric ) require commit <= target AND is_stable == true
CX_SCRATCH_MB 4096 // 4 GB memory-hard scratchpad (+ 4 GB dataset = 8 GB total mining memory)
CX_N 32 // linear system dimension
CX_ROUNDS 100,000 // sequential gradient iterations
CX_LR_SHIFT 18 // learning rate = 1/(2^18)
CX_LAM 100 // regularization parameter (λ)
CX_CHECKPOINT_INTERVAL 6,250 // rounds/16, Merkle-committed
CX_STABILITY_K 4 // perturbation probes per attempt
CX_STABILITY_GRADIENT_STEPS 3 // refinement steps per probe
Scratchpad derivation Sequential SHA-256 chain // epoch-keyed, mmap-friendly
Verification Two-stage pipeline // cheap header check → full recompute
Stability Basin Verification
CONSENSUS-CRITICAL

A valid ConvergenceX proof must demonstrate that the solution x_final resides in a stable attractor basin. The verifier applies k deterministic perturbation probes and checks two acceptance rules per probe:

Local non-explosion d(t+1) <= d(t) + margin_eff // per gradient step
Global contraction d_final * c_den <= d0 * c_num + margin_eff // for large perturbations
Contraction ratio 7/10 // epoch-invariant V1
Perturbation scale 3 // uniform in [-scale, +scale]
Stability LR shift 20 // lr_shift + 2 (more conservative)
DIFFICULTY ADJUSTMENT

cASERT bitsQ Retargeting

casert_next_difficulty()
CONSENSUS-CRITICAL

SOST implements cASERT bitsQ as the primary hardness regulator within the unified cASERT consensus-rate control system. Inspired by BCH's ASERT, the bitsQ controller performs per-block exponential difficulty adjustment in continuous Q16.16 log-space. Unlike legacy epoch-based retarget systems that wait for large windows, bitsQ corrects difficulty every single block with a 48-hour half-life and a per-block relative delta cap of 6.25% (1/16), producing smooth transitions and faster convergence to the target interval.

// Compute expected parent time from epoch anchor expected_pt = anchor_time + (parent_idx - anchor_idx) * 600 td = prev_time - expected_pt // Exponential cASERT bitsQ: next_bitsq = anchor_bitsq * 2^(-td / halflife) exponent = (-td * Q16_ONE) / CASERT_HALF_LIFE shifts = exponent >> 16 // integer part frac = exponent & 0xFFFF // fractional part // 2^frac via cubic polynomial (Horner's form, Q0.16) factor = Q16_ONE + polynomial_approx(frac) result = (anchor_bitsq * factor) >> 16 result = result << shifts // apply integer power-of-two // Per-block relative delta cap: 6.25% (1/16) new_powDiffQ = clamp( result, MIN_BITSQ, MAX_BITSQ )
TARGET_SPACING 600 seconds // 10-minute target block time
bitsQ Half-Life 43,200 seconds // 48 hours
MIN_BITSQ 65,536 // Q16_ONE — minimum difficulty
MAX_BITSQ 16,711,680 // 255 × Q16_ONE — maximum difficulty
Anchor rotation Per-epoch // resets at epoch boundary blocks
Encoding SOSTCompact Q16.16 // finer granularity than Bitcoin nBits
Arithmetic Integer-only // no floating point, no consensus drift
EQUALIZER

cASERT Controller

casert_mode_from_chain()
EQUALIZER LAYER

cASERT (Contextual Adaptive Stability & Emission Rate Targeting) is the unified consensus-rate control system. It integrates three components: (1) bitsQ Q16.16 primary hardness regulator, (2) equalizer profiles E4–H9 that adjust ConvergenceX stability parameters, and (3) anti-stall recovery. The equalizer uses 5 EWMA signals to compute a weighted control signal U, which selects a profile from deep easing (E4) through baseline (B0) to maximum hardening (H9). H10–H12 are defined in code but capped at H9.

// Signals (all Q16.16 fixed-point) r = log2(TARGET_SPACING / dt) // instantaneous log-ratio L = height - floor((time - GENESIS_TIME) / 600) // schedule lag S = EWMA(r, alpha=32/256) // 8-block short window M = EWMA(r, alpha=3/256) // 96-block long window V = EWMA(|r - S|, alpha=16/256) // 16-block volatility I = leaky integrator(L, rho=253/256) // ±100 cap // Control signal (lag-dominant, prevents oscillation) U = 0.05·r + 0.40·L + 0.15·I + 0.05·(S-M) + 0.02·V H = clamp(U >> 16, E4=-4, H9=9) // max hardening (H10-H12 defined but capped) // Safety rules if lag <= 0 (behind schedule): H = min(H, B0) // never harden when behind if chain.size() < 10: H = min(H, B0) // require 10 blocks // Slew rate: ±1 profile level per block (prevents oscillation) H = clamp(H, prev_H - 1, prev_H + 1)
E4 DEEP EASING
scale=1 · k=3 · margin=240 · steps=3
Maximum easing: widest margin, fewest stability probes. Only after 6h extra at B0.
E3–E1
scale=1 · k=3–4 · margin=240–200 · steps=3–4
Easing profiles. Only after 6h extra at B0.
B0 BASELINE
scale=1 · k=4 · margin=185 · steps=4
Default operating profile. Balanced stability test.
H1–H5
scale=1–2 · k=4–6 · margin=175–135 · steps=4–6
Progressive hardening. Tighter margin, more probes.
H6–H9 MAX
scale=2–3 · k=6–8 · margin=130–110 · steps=6–8
Maximum hardening. H10–H12 defined in code but capped at H9.
// Zone-based decay to B0 — mining only // Activation: max(ahead × 600s, 7200s) — floor 2 hours stall = now - last_block_time threshold = max(ANTISTALL_FLOOR=7200, ahead × 600) if stall >= threshold: // Zone decay rates (current level determines speed): // H9–H7: 600s/level (fast) — 1800s total // H6–H4: 900s/level (medium) — 2700s total // H3–H1: 1200s/level (slow) — 3600s total // Decays to B0. Easing E1–E4 only after 6h extra at B0. H = zone_decay(H, stall - threshold)

Key design properties:
• 17 profiles E4(-4) through H12(+12); H10–H12 defined but capped at H9. Active range: E4–H9.
• Lag-dominant gains (60% of total signal) prevent oscillation between E4 and H9.
• Slew rate ±1/block ensures smooth profile transitions.
• Behind schedule → cap at B0 prevents hardening when blocks are slow.
• Anti-stall: zone-based decay to B0 (H9–H7: 600s/lvl, H6–H4: 900s/lvl, H3–H1: 1200s/lvl). Easing E1–E4 only after 6h extra at B0.

CASERT_H_MIN -4 // E4 (deep easing)
CASERT_H_MAX 9 // H9 (max hardening; H10-H12 defined but capped)
K_R / K_L / K_I / K_B / K_V 0.05 / 0.40 / 0.15 / 0.05 / 0.02 // lag-dominant (60%)
SLEW_RATE ±1 // profile level per block
ANTISTALL_FLOOR 7200 // 2 hours minimum before decay
ANTISTALL_DECAY zone-based // H9-H7: 600s/lvl, H6-H4: 900s/lvl, H3-H1: 1200s/lvl
Safety rules Behind schedule → cap B0 · <10 blocks → cap B0
ENCODING & VALIDATION

SOSTCompact & MTP

SOSTCompact Q16.16
CONSENSUS

Difficulty is encoded as a Q16.16 fixed-point value in block headers, providing finer granularity than Bitcoin's nBits compact format. Deterministic bidirectional conversion between compact and full 256-bit target ensures consensus-safe retarget math and bit-for-bit reproducibility.

Format Q16.16 fixed-point // uint32
GENESIS_BITSQ 765,730 (11.6841 in Q16.16, calibrated)
MIN_BITSQ Easiest allowed target
MAX_BITSQ Hardest allowed target
Timestamp Discipline
CONSENSUS

Block timestamps are validated against Median Time Past (MTP) to prevent manipulation affecting difficulty. Combined with cASERT anchoring, this creates stable timing even under individually noisy blocks.

MTP_WINDOW 11 blocks
MAX_FUTURE_DRIFT 600 seconds
Rule: ts > MTP Strict monotonicity
Rule: ts ≤ now + drift Bounded acceptance
CHAIN PARAMETERS

Consensus Constants

Network Configuration
IMMUTABLE
MAINNET_GENESIS_UTC 1773597600 // 2026-03-15 18:00:00 UTC
BLOCKS_PER_EPOCH 131,553 // ≈2.5 years (Feigenbaum α)
TARGET_SPACING 600 seconds // 10-minute blocks
MAGIC CXPOW3 + NETWORK_ID // unique wire identifier
NETWORK_ID SHA256("SOST/CONVERGENCEX/mainnet")[:4]
Block header MAGIC + "HDR2" + core(72B) + cp_root(32B) + nonce(4B) + extra(4B)
Block ID SHA256( header || "ID" || commit )
Block key (anti-grind) SHA256( prev_hash || "BLOCK_KEY" ) // tip-bound only
Chainwork Bitcoin-style: floor(2^256 / (target + 1)) per block. Cumulative = sum of all block work.
Chain selection Best chain by cumulative work, not longest chain. The chain with the highest total accumulated work wins. This prevents attacks using many easy blocks to outpace a shorter chain with more real work. Same approach as Bitcoin.
Fork resolution Atomic. If a better chain is found, the node disconnects current blocks, connects the new chain, and recovers orphaned transactions to the mempool. If any block in the new chain fails validation, the entire reorganization is aborted and the original chain is restored. MAX_REORG_DEPTH = 500 blocks (~3.5 days).
HARDWARE

System Requirements

Mining is memory-hard (ASIC resistant), but verification is lightweight (anyone can run a node). The miner must build and hold the full 4 GB dataset and 4 GB scratchpad in memory to solve the ConvergenceX puzzle. The node only verifies the compact Transcript V2 proof — SHA256 hashes and merkle checks, no dataset required.

FULL NODE
~500 MB RAM
RAM~500 MB (no dataset, no scratchpad)
CPUAny modern processor
DiskMinimal (~1 KB per block)
System2 GB total, any OS
Verify speed~0.2 ms per block (Transcript V2)
MINER
8 GB RAM
RAM8 GB min (4 GB dataset + 4 GB scratchpad)
CPUModern multi-core (L3 cache helps)
DiskMinimal
System16 GB total recommended
Per attempt100K rounds + dataset/scratchpad I/O
DESIGN

Core Principles

DETERMINISTIC
Zero floating point in consensus. Integer-only arithmetic guarantees identical results on every architecture. Same input → same output, unconditionally.
CPU-ORIENTED
8 GB total mining memory (4 GB scratchpad + 4 GB dataset) with 100,000 sequential iterations. Node validation requires only ~500 MB. Throughput is bounded by memory bandwidth and latency, not raw compute — making ASIC development economically impractical.
ADAPTIVE
Per-block cASERT retargeting with bitsQ + equalizer. The chain converges to its target interval within hours, not days. No retarget whiplash.
LAUNCH-SAFE
cASERT degrades stability requirements under thin hashrate, ensuring the chain remains mineable and stable from genesis. Security grows with the network.
VERIFIABLE
Transcript V2 verification: cheap header/target checks for fast sync, 11-phase segment + round witness verification (~0.2ms) for standard validation, full ConvergenceX recomputation for deep validation. Merkle-committed segments and checkpoints enable SPV-friendly proof structures.
ANTI-GRINDING
Block key derives from chain tip only. All miners solve the same linear system for a given tip — per-attempt uniqueness comes from nonce/extra_nonce, not from the challenge itself.
PoW COMPARISON

Bitcoin vs Monero vs SOST

Proof-of-Work Architecture Comparison
Property Bitcoin (SHA-256d) Monero (RandomX) SOST (ConvergenceX)
PoW verify cost~1μs~50ms~5–30s
Memory (mining)Negligible256MB–2GB8GB (4GB scratchpad + 4GB dataset)
Memory (node)Negligible~256MB~500MB (no scratchpad/dataset)
ASIC resistanceNoneHighVery high
Full sync time~hours~days~weeks
Fast sync time~minutes~hours~minutes
Verification layers448
Difficulty adjustEvery 2016 blocksEvery block (LWMA)Every block (cASERT exp.)
Block time600s120s600s
Anti-stallNoneLWMAcASERT Decay (2h floor, 1 level/20min)
Anti-accelerationNoneLWMAcASERT Equalizer E4–H9 (±1/block)
EmissionHalving / 210K blocksTail emissionSmooth exp. decay (q=e)
Max supply21M BTCInfinite~4,669,201 SOST
Constitutional reserveNoneNone25% gold + 25% PoPC