---
language:
- code
license: apache-2.0
tags:
- tokenizer
- binary-analysis
- binary-tokenization
- bpe
- byte-pair-encoding
- malware-analysis
- reverse-engineering
- security
- x86-64
- arm64
- elf
- pe
library_name: tokenizers
pipeline_tag: feature-extraction
---

# glaurung-binary-tokenizer-002

A cross-platform BPE tokenizer for binary executables and machine code. Trained using advanced chunked training with deduplication on 23 GB of diverse binaries spanning Linux and Windows platforms.

**🔗 Model**: [`mjbommar/glaurung-binary-tokenizer-002`](https://huggingface.co/mjbommar/glaurung-binary-tokenizer-002)
**📊 Dataset**: [`mjbommar/binary-30k-tokenized`](https://huggingface.co/datasets/mjbommar/binary-30k-tokenized)
**📄 Paper**: *Binary BPE: Cross-Platform Tokenization for Binary Analysis* (arXiv preprint coming soon)

## Overview

- **Vocabulary Size**: 65,536 tokens (2^16)
- **Token Composition**: 256 base bytes + 65,273 learned merges + 7 special tokens
- **Average Token Length**: 3.749 bytes
- **3-byte Instructions**: 16.5% of vocabulary (10,800 tokens)
- **Compression Ratio**: ~2.6 bytes/token on typical binaries

---

## Training Configuration

**Training Corpus**:
- Source: [`mjbommar/binary-30k-tokenized`](https://huggingface.co/datasets/mjbommar/binary-30k-tokenized)
- Size: ~23 GB (24.7 billion bytes)
- Processed Chunks: 40,574 total (37,083 unique + 8,454 duplicates reused)
- Platforms: Linux (Alpine, Debian, Ubuntu - ELF), Windows (8, 10, 11 - PE)
- Architectures: x86-64, x86-32, ARM64

**Training Parameters**:
- Vocabulary size: 65,536 (including 7 special tokens)
- Min frequency: 4
- Chunk size: 4,194,304 bytes (4 MB)
- Training method: Chunked BPE with deduplication and support-based merge combination
- Allowed lengths: DEFAULT (1-16 bytes)
- Training duration: ~8-9 hours

---

## Vocabulary Statistics

**Composition**:
- Base bytes (0-255): 256 tokens
- Learned merges: 65,273 tokens
- Special tokens: 7 tokens (`<|start|>`, `<|end|>`, `<|pad|>`, `<|unk|>`, `<|cls|>`, `<|sep|>`, `<|mask|>`)
- **Total**: 65,536 tokens

**Quality Metrics**:
- All tokens reachable: ✓ Yes
- Valid merges: 65,273 / 65,273
- Power-of-2 size: ✓ Yes (2^16)

---

## Token Length Distribution

| Length | Count | Percentage | Description |
|--------|-------|------------|-------------|
| 1 byte | 256 | 0.4% | Base bytes |
| 2 bytes | 28,561 | 43.6% | Byte pairs (most common patterns) |
| 3 bytes | 10,800 | 16.5% | Complete x86-64 instructions |
| 4 bytes | 14,376 | 21.9% | Instructions with operands |
| 5 bytes | 2,780 | 4.2% | Complex patterns |
| 6 bytes | 2,213 | 3.4% | Complex patterns |
| 7 bytes | 1,167 | 1.8% | Complex patterns |
| 8 bytes | 2,329 | 3.6% | Multi-byte sequences |
| 9+ bytes | 3,045 | 4.6% | Long patterns |

**Average Token Length**: 3.749 bytes

---

## Byte Content Analysis

**Content Categories**:
- Contains NULL byte (0x00): 17,418 tokens (26.6%)
- ASCII printable (0x20-0x7E): 9,478 tokens (14.5%)
- All ASCII (<0x80): 20,816 tokens (31.8%)
- High bytes (≥0x80): 44,711 tokens (68.2%)

**Most Common Bytes in Tokens**:
- `0x00` (NULL): 34,482 occurrences - Padding and alignment
- `0xFF`: 6,545 occurrences - Sentinel values
- `0x48` (REX.W): 3,419 occurrences - x86-64 REX prefix
- `0x8B` (MOV): 2,486 occurrences - x86-64 MOV opcode
- `0x40` (@): 4,538 occurrences - ASCII and instruction patterns

---

## Sequence Coverage

**N-byte Sequence Diversity**:
| Length | Learned Tokens | Possible Sequences | Coverage |
|--------|----------------|-------------------|----------|
| 1-byte | 256 | 256 | 100.00% |
| 2-byte | 28,561 | 65,536 | 43.58% |
| 3-byte | 10,800 | 16,777,216 | 0.064% |
| 4-byte | 14,376 | 4,294,967,296 | 0.00034% |

**Notable Achievement**: 43.6% coverage of all possible 2-byte sequences - excellent for pattern recognition.

---

## Files

- `tokenizer-65536.json` - Trained tokenizer model (2.4 MB)
- `analysis_results.json` - Detailed analysis statistics
- `original_README.md` - Original README from HuggingFace

---

## Usage

**Load from HuggingFace Hub**:
```python
from tokenizers import Tokenizer

# Load directly from HuggingFace
tokenizer = Tokenizer.from_pretrained("mjbommar/glaurung-binary-tokenizer-002")
```

**Load from local file**:
```bash
# With bbpe CLI
bbpe encode --tokenizer tokenizer-65536.json /path/to/binary
bbpe info tokenizer-65536.json
```

**Complete Python Example**:
```python
from tokenizers import Tokenizer

# Load from HuggingFace or local file
tokenizer = Tokenizer.from_pretrained("mjbommar/glaurung-binary-tokenizer-002")
# OR: tokenizer = Tokenizer.from_file("tokenizer-65536.json")

# Read binary file and decode as latin-1 (preserves all byte values 0-255)
with open("/usr/bin/ls", "rb") as f:
    data = f.read()
    data_str = data.decode("latin-1")

# Encode the binary data
encoding = tokenizer.encode(data_str)
print(f"File size: {len(data)} bytes")
print(f"Total tokens: {len(encoding.ids)}")
print(f"Compression: {len(data) / len(encoding.ids):.3f} bytes/token")

# First 10 tokens
for i, (token_id, token) in enumerate(zip(encoding.ids[:10], encoding.tokens[:10])):
    token_bytes = token.encode("latin-1")
    print(f"  Token {i}: ID={token_id:5d} hex={token_bytes.hex():20s} ({len(token_bytes)} bytes)")

# Decode tokens back to bytes
decoded_str = tokenizer.decode(encoding.ids)
decoded_bytes = decoded_str.encode("latin-1")
assert decoded_bytes == data  # Perfect reconstruction
```

**Example output for `/usr/bin/ls` (142,312 bytes)**:
```
File size: 142312 bytes
Total tokens: 54537
Compression: 2.609 bytes/token

First 10 tokens:
  Token 0: ID=  127 hex=7f                   (1 bytes)
  Token 1: ID= 2382 hex=454c                 (2 bytes)
  Token 2: ID= 5923 hex=4602                 (2 bytes)
  Token 3: ID=  394 hex=0101                 (2 bytes)
  Token 4: ID=  268 hex=000000000000         (6 bytes)
  Token 5: ID=  259 hex=000000               (3 bytes)
  Token 6: ID=  295 hex=0300                 (2 bytes)
  Token 7: ID= 2124 hex=3e00                 (2 bytes)
  Token 8: ID=  271 hex=01000000             (4 bytes)
  Token 9: ID=59106 hex=306d                 (2 bytes)

Decoded: 7f454c4602010100000000000000000003003e0001000000306d...
(ELF header: 7f 45 4c 46 = ELF magic bytes)
```

---

## Performance Characteristics

**Compression on Real-World Binaries**:

| Binary | Size | Tokens | bytes/token |
|--------|------|--------|-------------|
| bash | 1.38 MB | 602,719 | 2.399 |
| python3.12 | 7.65 MB | 2,997,303 | 2.676 |
| gcc-13 | 0.98 MB | 375,331 | 2.726 |
| ls | 0.14 MB | 54,537 | 2.609 |
| grep | 0.18 MB | 73,500 | 2.542 |

**Average**: 2.590 bytes/token

**Information-Theoretic Efficiency**:
- Binary entropy: ~6.5 bits/byte
- Theoretical optimal: 2.46 bytes/token
- Actual performance: 2.590 bytes/token
- **Efficiency: 95.0%** of theoretical optimum

---

## Key Features

**Instruction-Aware Patterns**:
- REX prefixes: `0x48`, `0x4c`, `0x4d` (x86-64 64-bit operands)
- Common opcodes: `0x8b` (MOV), `0x89` (MOV), `0xe8` (CALL)
- ModR/M patterns: `0xc0`, `0x45`, `0x5d`

**Common Binary Patterns**:
- Padding: `0xcc 0xcc` (INT3 debug breakpoints), `0x90 0x90` (NOP sleds)
- Alignment: `0x00 0x00 0x00 0x00` (NULL padding)
- String terminators: `0x00` at word boundaries

**String-Rich Vocabulary**:
- 11.81% of vocabulary contains function names, paths, and library references
- Better semantic understanding than standard BPE

---

## Comparison with Other Tokenizers

**vs. binary-tokenizer-001 Series** (this repository):

| Metric | 4K | 8K | 16K | 64K (this) | Improvement |
|--------|----|----|-----|------------|-------------|
| Vocab size | 4,096 | 8,192 | 16,384 | 65,536 | 4-16x larger |
| Avg token length | 3.000 | 3.312 | 3.498 | 3.749 | +25% vs 4K |
| 3-byte tokens % | 20.6% | 21.7% | 20.5% | 16.5% | Different focus |
| 2-byte coverage | 3.0% | 5.6% | 10.9% | 43.6% | 14x better |
| Compression (ls) | 2.00 | 2.17 | 2.39 | 2.61 | +30% vs 4K |
| Training method | Standard | Standard | Standard | Chunked+dedup | Advanced |

**Key Advantages of 64K Vocabulary**:
- **43.6% 2-byte coverage**: Captures nearly half of all possible byte pairs
- **Chunked training**: Deduplication-aware training improves merge quality
- **Better compression**: 2.609 bytes/token vs 2.0 bytes/token (4K)
- **Longer patterns**: 3.749 byte average vs 3.0 bytes (4K)
- **String-rich**: 11.81% vocabulary contains semantic strings

---

## Citation

If you use this tokenizer in your research, please cite:

```bibtex
@article{bommarito2025binarybpe,
  title={Binary BPE: Cross-Platform Tokenization for Binary Analysis},
  author={Bommarito II, Michael J.},
  journal={arXiv preprint},
  year={2025},
  note={Preprint coming soon}
}
```

**Also cite the original Glaurung tokenizer**:
```
Glaurung Binary Tokenizer 002
64K Binary Tokenizer for Neural Language Models
Vocabulary: 65,536 tokens (256 base + 65,273 merges + 7 special)
Training: October-November 2025
Training Method: Chunked BPE with deduplication (bbpe v0.3.2)
Dataset: 23GB binaries-small (40,574 chunks, 8,454 duplicates)
Performance: 2.590 bytes/token (95% of theoretical optimum)
HuggingFace: mjbommar/glaurung-binary-tokenizer-002
```

**Author**: Michael J. Bommarito II ([michael.bommarito@gmail.com](mailto:michael.bommarito@gmail.com))

---

## License

**Apache License 2.0**

This tokenizer is part of the [Glaurung](https://github.com/mjbommar/glaurung) project.

---

**Generated**: November 13, 2025
**Original Model**: `mjbommar/glaurung-binary-tokenizer-002`
**Training Tool**: bbpe v0.3.2
**Analysis Script**: `analyze_tokenizer.py`