decryption_guide.md

BCV3 Decryption Guide

Overview

The BCV3 dataset includes encrypted question-answer pairs to protect intellectual property while allowing community review. This guide explains how to decrypt them.

Encryption Details

• Algorithm: AES-256-GCM (Galois/Counter Mode)
• Key Derivation: SHA-256 hash of the passphrase
• IV Format: 16-byte random initialization vector (base64-encoded)
• Authentication: 16-byte GCM tag for integrity verification

Key

Use the following passphrase to derive the AES-256-GCM key:

A_Visual_Vertical_Verifiable_Benchmark_for_Multimodal_Browsing_Agents

Data Format

The dataset uses one canonical format: train.jsonl (optimized and deduplicated):

{
  "id": "...",
  "category": "...",
  "sub_category": "...",
  "image": "...",
  "image_paths": "[...JSON string...]",
  "encrypted_question": "{...JSON string...}",
  "encrypted_answer": "{...JSON string...}",
  "metadata": "{...JSON string (includes trajectory)...}",
  "sub_goals": "[...JSON string...]"
}

Key optimizations:

• ✓ No redundant trajectory: trajectory is inside metadata, not duplicated at top level
• ✓ JSON strings: All fields are serialized as JSON for HuggingFace Dataset Viewer compatibility
• ✓ Space savings: 28.1% reduction from original (2.0 MB → 1.44 MB)

Legacy format: The original bcv3_encrypted.jsonl (with redundant top-level trajectory) is archived in /archive/ for reference only.

Requirements

pip install cryptography

Usage

1. Decrypt the whole dataset to a single JSON file

python scripts/decryption_script.py \
  --input data/train.jsonl \
  --key "A_Visual_Vertical_Verifiable_Benchmark_for_Multimodal_Browsing_Agents" \
  --output decrypted_bcv3.json

Options:

• --keep-encrypted: Keep encrypted fields in output (default: remove them)

Example output:

[
  {
    "id": "001_Culture_Art_L3_p2_t2_m0_r2_w0_c0_g5",
    "question": "The content in Figure 1 is a classic of a certain religion...",
    "answer": "2",
    "metadata": {...},
    ...
  }
]

2. Batch decrypt to per-sample JSON files

# Create a key file
echo "A_Visual_Vertical_Verifiable_Benchmark_for_Multimodal_Browsing_Agents" > key.txt

# Run batch decryption
python scripts/decrypt_batch.py \
  --input data/train.jsonl \
  --key-file key.txt \
  --output-dir decrypted_samples/

Options:

• --keep-encrypted: Keep encrypted fields in output (default: remove them)

Output structure:

decrypted_samples/
├── 001_Culture_Art_L3_p2_t2_m0_r2_w0_c0_g5.json
├── 002_Culture_Art_...json
└── ...

3. Using archived legacy format (optional)

If you need to work with the archived original format:

# Scripts support legacy bcv3_encrypted.jsonl (archived in /archive/)
python scripts/decryption_script.py \
  --input ../archive/bcv3_encrypted.jsonl \
  --key "A_Visual_Vertical_Verifiable_Benchmark_for_Multimodal_Browsing_Agents" \
  --output decrypted_legacy.json

The scripts automatically detect and handle both formats.

Python API

from encryption_utils import derive_key, decrypt_text

key_str = "A_Visual_Vertical_Verifiable_Benchmark_for_Multimodal_Browsing_Agents"
key = derive_key(key_str)

# Decrypt a single encrypted field (dict with iv/ciphertext/tag)
encrypted_dict = {
    "iv": "...",
    "ciphertext": "...",
    "tag": "..."
}
plaintext = decrypt_text(encrypted_dict, key)

Verification

Test decryption with a small sample:

head -1 data/train.jsonl | python3 << 'EOF'
import sys
import json
sys.path.insert(0, 'scripts')
from encryption_utils import derive_key, decrypt_text

key = derive_key("A_Visual_Vertical_Verifiable_Benchmark_for_Multimodal_Browsing_Agents")
obj = json.loads(sys.stdin.read())
enc_q = json.loads(obj['encrypted_question'])
enc_a = json.loads(obj['encrypted_answer'])
print("Question:", decrypt_text(enc_q, key)[:80])
print("Answer:", decrypt_text(enc_a, key))
EOF

Troubleshooting

"Decryption failed" or integrity error

• Verify you're using the exact passphrase (case-sensitive)
• Ensure the encrypted data has valid iv/ciphertext/tag fields

"Unrecognized format" warning

• The script will skip records that don't have encrypted fields
• Check that your input file is in the expected format

File not found

• Ensure paths are relative to the script directory or use absolute paths
• For batch mode, the key file must exist and be readable

Questions?

For issues or questions about decryption, please refer to the main README or file an issue on the repository.