Grok — PS-SHA∞ Hash-Chaining Pseudocode

Date: 2026-03-28
Source: Grok (xAI)
Context: Exact hash-chaining logic pseudocode for BlackRoad's immutable memory

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Core Implementation

``python


PS-SHA∞: Infinite Append-Only SHA-256 Hash Chain

import hashlib
import time
from typing import Dict, Any

class PSSHAInfiniteJournal:
def __init__(self):
self.head_hash: str = "0" * 64 # Genesis hash (all zeros)
self.journal: list[Dict[str, Any]] = []

def append(self, actor_id: str, channel: str, payload: Any) -> str:
# 1. Capture current state
previous_hash = self.head_hash
timestamp = int(time.time() * 1000)

# 2. Build structured entry (never mutated)
entry: Dict[str, Any] = {
"timestamp": timestamp,
"actor_id": actor_id,
"channel": channel,
"payload_hash": hashlib.sha256(str(payload).encode()).hexdigest(),
"previous_hash": previous_hash
}

# 3. Serialize and hash (infinite chaining)
serialized = str(entry).encode('utf-8') + previous_hash.encode('utf-8')
new_hash = hashlib.sha256(serialized).hexdigest()

# 4. Commit
self.head_hash = new_hash
self.journal.append(entry)

# 5. Witness to RoadChain / D1
# witness_to_roadchain(new_hash, entry)

return new_hash

def verify_chain(self, target_index: int = -1) -> bool:
current_hash = "0" * 64
for i, entry in enumerate(self.journal[:target_index + 1]):
serialized = str(entry).encode('utf-8') + current_hash.encode('utf-8')
computed = hashlib.sha256(serialized).hexdigest()
if computed != entry.get("previous_hash") and i > 0:
return False
current_hash = computed
return True
`

RoadTrip Example Flow

1. User types in #creative → append(actor="you", channel="#creative", payload="need battle music")
2. Build entry → new_hash = SHA256(entry + previous_head)`
3. Hash witnessed to D1 (fast chat) + RoadChain (on-chain finality)
4. Any agent references that hash → full immutable history

Key Properties

Infinite & append-only — nothing ever deleted or altered

Cryptographic proof — recompute chain from genesis proves authenticity

Constant-time verification — only need head hash

Portable — journal travels with RoadID across any cluster

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Raw Grok output preserved verbatim. Filed 2026-03-28.