Clarify ORCA track semantics and remove legacy unsealer

README.md

@@ -48,10 +48,14 @@ cp .env.example .env
   --include-task-name task_011_cell_migration_wound_healing
 ```
 
-The 16 ORCA task definitions and inputs are included normally. ORCA itself and
-an ORCA-configured image are never distributed; evaluators obtain ORCA from its
-official provider and follow the runtime repository's
-[local-image tutorial](https://github.com/ApodexAI/FrontierAgent/blob/main/benchmarks/frontierchallenge/docs/providers/orca.md).
+The 16 task definitions that execute ORCA and their inputs are included
+normally. ORCA itself and an ORCA-configured image are never distributed;
+evaluators obtain ORCA from its official provider and follow the runtime
+repository's [local-image tutorial](https://github.com/ApodexAI/FrontierAgent/blob/main/benchmarks/frontierchallenge/docs/providers/orca.md).
+
+Track membership follows what a task executes, not software named in supplied
+files. For example, `task_098_orca_claisen_thermochemistry` reads precomputed
+ORCA output without running ORCA, so it remains in the open track.
 
 Verify a downloaded solve package with:
 

tools/unseal_statement.py

@@ -1,67 +0,0 @@
-#!/usr/bin/env python3
-"""Unseal one or more FrontierChallenge English task statements."""
-from __future__ import annotations
-
-import argparse
-import gzip
-import hashlib
-import hmac
-import io
-import struct
-import tarfile
-from pathlib import Path
-
-MAGIC = b"FCREF1\n"
-PASSWORD = "apodex.ai"
-
-
-def decrypt(blob: bytes, password: str) -> bytes:
-    if not blob.startswith(MAGIC):
-        raise ValueError("not a FrontierChallenge sealed archive")
-    offset = len(MAGIC)
-    salt = blob[offset:offset + 16]
-    tag = blob[offset + 16:offset + 48]
-    ciphertext = blob[offset + 48:]
-    material = hashlib.pbkdf2_hmac(
-        "sha256", password.encode("utf-8"), salt, 200_000, dklen=64
-    )
-    enc_key, mac_key = material[:32], material[32:]
-    expected = hmac.new(mac_key, ciphertext, hashlib.sha256).digest()
-    if not hmac.compare_digest(tag, expected):
-        raise ValueError("wrong password or corrupt archive")
-    blocks = (len(ciphertext) + 31) // 32
-    stream = b"".join(
-        hmac.digest(enc_key, struct.pack(">Q", counter), "sha256")
-        for counter in range(blocks)
-    )[:len(ciphertext)]
-    return bytes(left ^ right for left, right in zip(ciphertext, stream))
-
-
-def unseal(task: Path, password: str, force: bool) -> None:
-    target = task / "instruction.md"
-    if target.exists() and not force:
-        raise FileExistsError(f"{target} already exists; use --force to replace it")
-    plaintext = decrypt((task / "statement.fcref").read_bytes(), password)
-    with gzip.GzipFile(fileobj=io.BytesIO(plaintext), mode="rb") as gz:
-        with tarfile.open(fileobj=gz, mode="r:") as tar:
-            member = tar.getmember("instruction.md")
-            handle = tar.extractfile(member)
-            if handle is None:
-                raise ValueError(f"instruction.md missing from {task / 'statement.fcref'}")
-            target.write_bytes(handle.read())
-    print(target)
-
-
-def main() -> int:
-    parser = argparse.ArgumentParser()
-    parser.add_argument("tasks", nargs="+", type=Path)
-    parser.add_argument("--password", default=PASSWORD)
-    parser.add_argument("--force", action="store_true")
-    args = parser.parse_args()
-    for task in args.tasks:
-        unseal(task, args.password, args.force)
-    return 0
-
-
-if __name__ == "__main__":
-    raise SystemExit(main())