use 5+27 length for quadrable keys instead of 9+23

- reduces quadrable branching
- increases collision resistance
- good until year 2514

src/constants.h

@@ -1,3 +1,4 @@
 #pragma once
 
-const size_t MAX_SUBID_SIZE = 63;
+const size_t MAX_SUBID_SIZE = 63; // Statically allocated size in SubId
+const uint64_t MAX_TIMESTAMP = 17179869184; // Safety limit to ensure it can fit in quadrable key. Good until year 2514.

src/events.cpp

@@ -119,7 +119,7 @@ void verifyEventTimestamp(const NostrIndex::Event *flat) {
     uint64_t latest = now + cfg().events__rejectEventsNewerThanSeconds;
 
     if (ts < earliest) throw herr("created_at too early");
-    if (ts > latest) throw herr("created_at too late");
+    if (ts > latest || ts > MAX_TIMESTAMP) throw herr("created_at too late");
 }
 
 void parseAndVerifyEvent(const tao::json::value &origJson, secp256k1_context *secpCtx, bool verifyMsg, bool verifyTime, std::string &flatStr, std::string &jsonStr) {

src/events.h

@@ -51,7 +51,9 @@ std::string_view decodeEventPayload(lmdb::txn &txn, Decompressor &decomp, std::s
 std::string_view getEventJson(lmdb::txn &txn, Decompressor &decomp, uint64_t levId);
 
 inline quadrable::Key flatEventToQuadrableKey(const NostrIndex::Event *flat) {
-    return quadrable::Key::fromIntegerAndHash(flat->created_at(), sv(flat->id()).substr(0, 23));
+    uint64_t timestamp = flat->created_at();
+    if (timestamp > MAX_TIMESTAMP) throw herr("timestamp is too large to encode in quadrable key");
+    return quadrable::Key::fromIntegerAndHash(timestamp, sv(flat->id()).substr(0, 27));
 }