Kaidi Liu

15 papers Journal 10Unranked 5
YearRankTypeTitle / Venue / Authors
2025 J jnl
IEEE Trans. Veh. Technol.
Xiangfei Zheng, Kaidi Liu, Yujie Zhang, Hongwei Li
2025 J jnl
Frontiers Inf. Technol. Electron. Eng.
Xiangfei Zheng, Kaidi Liu, Hongwei Li
2024 J jnl
Comput. Electron. Agric.
Kaidi Liu, Yao Zhang, Tingyao Gao, Fanghui Tong, Pinghong Liu, Wenjing Li, Minzan Li
2024 J jnl
BMC Bioinform.
Tiecheng Wang, Yehuan Xu, Linjie Hu, Huiling Liu, Kaidi Liu, Shuo Zhang, Hao Chen, Hua Guo, Shaobin Feng
2023 conf
CRC
Jiahao Chen, Kaidi Liu, Yiran Liu, Guoliang Zhai, Taogang Hou, Xuan Pei
2023 J jnl
Comput. Electron. Agric.
Haiyang Zhang, Yao Zhang, Kaidi Liu, Shu Lan, Tinyao Gao, Minzan Li
2022 J jnl
J. Comput. Des. Eng.
Pan Shi, Zijian Zhao, Kaidi Liu, Feng Li
2022 J jnl
J. Comput. Des. Eng.
Kaidi Liu, Zijian Zhao, Pan Shi, Feng Li, He Song
2022 J jnl
Remote. Sens.
Zezhong Tian, Yao Zhang, Kaidi Liu, Zhenhai Li, Minzan Li, Haiyang Zhang, Jiangmei Wu
2022 J jnl
Comput. Electron. Agric.
Zezhong Tian, Yao Zhang, Haiyang Zhang, Zhenhai Li, Minzan Li, Jiangmei Wu, Kaidi Liu
2021 J jnl
J. Comput. Sci.
Guanghui Wang, Yufei Wang, Jimei Li, Kaidi Liu
2010 conf
FSKD
Yanjun Pang, Wei Pan, Kaidi Liu
2009 conf
BIFE
Kaidi Liu, Jin Wang, Yan-jun Pang
2009 conf
DBTA
Kaidi Liu, Jimei Hao, Yanjun Pang
2009 conf
ESIAT (2)
Kaidi Liu, Jin Wang, Yan-jun Pang, Jin Liu, Jun-hu Ruan
docs/apk-code-schema.md
← Index docs/apk-code-schema.md markdown
# APK Code Analysis — ClickHouse Schema

All tables follow the `ReplacingMergeTree(analysis_date)` pattern from
`docs/new-code-binja-schema.md`, except `code_apk_analysis_errors` which
uses `MergeTree()`.

**Companion PDD:** `APK_CODE_ANALYSIS_PDD-Tech_Annex.md` §7

---

## Table overview

| # | Table | Analog (Binja) | Engine | Key |
|---|-------|----------------|--------|-----|
| 1 | `code_apk_decompiled_methods_content` | `code_binja_decompiled_functions_content` | ReplacingMergeTree | `decompiled_method_hash` |
| 2 | `code_apk_decompiled_methods_references` | `code_binja_decompiled_functions_references` | ReplacingMergeTree | `(sha256, decompiled_method_hash)` |
| 3 | `code_apk_smali_methods_content` | `code_binja_disassembled_functions_content` | ReplacingMergeTree | `smali_method_hash` |
| 4 | `code_apk_smali_methods_references` | `code_binja_disassembled_functions_references` | ReplacingMergeTree | `(sha256, smali_method_hash)` |
| 5 | `code_apk_method_similarity_metrics` | `code_binja_function_similarity_metrics` | ReplacingMergeTree | `smali_method_hash` |
| 6 | `code_apk_cfg_methods` | `code_binja_cfg_functions` | ReplacingMergeTree | `smali_method_hash` |
| 7 | `code_binja_strings_raw` *(shared)* | — | Null (→ MV) | — |
| 8 | `code_apk_analysis_errors` | `function_analysis_errors_binja` | MergeTree | `(sha256, error_location, error_hash)` |

---

## Table 1: `code_apk_decompiled_methods_content`

**Analog:** `code_binja_decompiled_functions_content`

```sql
CREATE TABLE IF NOT EXISTS code_apk_decompiled_methods_content (
    decompiled_method_hash FixedString(64),          -- SHA-256 of normalized Java source
    decompiled_method String CODEC(ZSTD(3)),          -- Full Java method source
    decompiled_method_type Enum8('USER'=1, 'LIBRARY'=2, 'UNKNOWN'=5) DEFAULT 'UNKNOWN',
    decompiled_has_string_encryption UInt8 DEFAULT 0,
    decompiled_has_reflection_calls UInt8 DEFAULT 0,
    decompiled_excessive_goto_count UInt8 DEFAULT 0,
    analysis_date DateTime64(3, 'UTC'),

    INDEX idx_method_content_token lower(decompiled_method) TYPE tokenbf_v1(32768, 3, 0) GRANULARITY 1
) ENGINE = ReplacingMergeTree(analysis_date)
ORDER BY decompiled_method_hash;
```

## Table 2: `code_apk_decompiled_methods_references`

**Analog:** `code_binja_decompiled_functions_references`

```sql
CREATE TABLE IF NOT EXISTS code_apk_decompiled_methods_references (
    sha256 FixedString(64),
    decompiled_method_hash FixedString(64),
    smali_method_hash Nullable(FixedString(64)),
    decompiled_class_name LowCardinality(String),
    decompiled_method_name LowCardinality(String),
    decompiled_method_signature String,               -- Dalvik descriptor: (Landroid/os/Bundle;)V
    decompiled_method_prototype String,               -- Java-style: void onCreate(Bundle)
    functions_caller Array(String),
    functions_call Array(String),
    analysis_date DateTime64(3, 'UTC'),

    INDEX idx_decompiled_class_name decompiled_class_name TYPE tokenbf_v1(32768, 3, 0) GRANULARITY 1,
    INDEX idx_decompiled_method_name decompiled_method_name TYPE tokenbf_v1(32768, 3, 0) GRANULARITY 1,
    INDEX idx_functions_caller functions_caller TYPE tokenbf_v1(32768, 3, 0) GRANULARITY 1,
    INDEX idx_functions_call functions_call TYPE tokenbf_v1(32768, 3, 0) GRANULARITY 1
) ENGINE = ReplacingMergeTree(analysis_date)
ORDER BY (sha256, decompiled_method_hash);
```

## Table 3: `code_apk_smali_methods_content`

**Analog:** `code_binja_disassembled_functions_content`

```sql
CREATE TABLE IF NOT EXISTS code_apk_smali_methods_content (
    smali_method_hash FixedString(64),                -- SHA-256 of normalized smali body
    smali_method String CODEC(ZSTD(3)),               -- Full smali method body
    smali_method_type Enum8('USER'=1, 'LIBRARY'=2, 'UNKNOWN'=5) DEFAULT 'UNKNOWN',
    smali_instructions_count UInt32,
    smali_register_count UInt16,
    smali_has_string_encryption UInt8 DEFAULT 0,
    smali_has_reflection_calls UInt8 DEFAULT 0,
    smali_excessive_goto_count UInt8 DEFAULT 0,
    smali_flattened_score Float64 DEFAULT 0.0,       -- Control flow flattening score (0.01.0)
    smali_mba_score Float64 DEFAULT 0.0,             -- Mixed boolean-arithmetic score (0.01.0)
    analysis_date DateTime64(3, 'UTC'),

    INDEX idx_smali_ngram smali_method TYPE ngrambf_v1(3, 32768, 3, 0) GRANULARITY 1,
    INDEX idx_smali_method_type smali_method_type TYPE set(3) GRANULARITY 1,
    INDEX idx_smali_instr_count smali_instructions_count TYPE minmax GRANULARITY 4,
    INDEX idx_smali_reg_count smali_register_count TYPE minmax GRANULARITY 4,
    INDEX idx_smali_flattened smali_flattened_score TYPE minmax GRANULARITY 4,
    INDEX idx_smali_mba smali_mba_score TYPE minmax GRANULARITY 4
) ENGINE = ReplacingMergeTree(analysis_date)
ORDER BY smali_method_hash;
```

## Table 4: `code_apk_smali_methods_references`

**Analog:** `code_binja_disassembled_functions_references`

```sql
CREATE TABLE IF NOT EXISTS code_apk_smali_methods_references (
    sha256 FixedString(64),
    smali_method_hash FixedString(64),
    decompiled_method_hash Nullable(FixedString(64)),
    smali_class_name LowCardinality(String),
    smali_method_name LowCardinality(String),
    smali_method_signature String,
    analysis_date DateTime64(3, 'UTC'),

    INDEX idx_smali_class_name smali_class_name TYPE tokenbf_v1(32768, 3, 0) GRANULARITY 1,
    INDEX idx_smali_method_name smali_method_name TYPE tokenbf_v1(32768, 3, 0) GRANULARITY 1
) ENGINE = ReplacingMergeTree(analysis_date)
ORDER BY (sha256, smali_method_hash);
```

## Table 5: `code_apk_method_similarity_metrics`

**Analog:** `code_binja_function_similarity_metrics`

Content-based fuzzy matching table. Structural/CFG scalars (block_count, edge_count, etc.)
are in `code_apk_cfg_methods` (Table 6) — this table holds only fuzzy hashes and MinHash.

```sql
CREATE TABLE IF NOT EXISTS code_apk_method_similarity_metrics (
    smali_method_hash FixedString(64),
    -- Raw smali fuzzy hashes (analog: ssdeep_disassembly / tlsh_disassembly)
    ssdeep_smali Nullable(String),
    tlsh_smali Nullable(FixedString(72)),
    -- Semantically normalized smali fuzzy hashes (analog: ssdeep_llil / tlsh_llil)
    ssdeep_smali_normalized Nullable(String),
    tlsh_smali_normalized Nullable(FixedString(72)),
    minhash Array(UInt8),
    analysis_date DateTime64(3, 'UTC'),

    INDEX idx_ssdeep ssdeep_smali TYPE bloom_filter GRANULARITY 1,
    INDEX idx_tlsh tlsh_smali TYPE bloom_filter GRANULARITY 1,
    INDEX idx_ssdeep_norm ssdeep_smali_normalized TYPE bloom_filter GRANULARITY 1,
    INDEX idx_tlsh_norm tlsh_smali_normalized TYPE bloom_filter GRANULARITY 1
) ENGINE = ReplacingMergeTree(analysis_date)
ORDER BY smali_method_hash;
```

## Table 6: `code_apk_cfg_methods`

**Analog:** `code_binja_cfg_functions` (see `db_migration/cfg_functions_ddl.sql`)

Structural and topological features computed from smali CFG. All fields mirror
the Binja table with APK-appropriate naming.

```sql
CREATE TABLE IF NOT EXISTS code_apk_cfg_methods (
    -- Identity
    smali_method_hash FixedString(64),

    -- Tier 0: Exact structural match
    cfg_topology_hash FixedString(16),

    -- Tier 1: Structural pre-filtering
    block_count UInt16,
    edge_count UInt16,
    cfg_instructions_count UInt32,            -- Dalvik instruction count (analog: llil_total_operations)
    call_count UInt16,
    cyclomatic_complexity UInt16,
    loop_count UInt16,
    max_depth UInt16,
    max_fan_out UInt16,
    md_index_topdown UInt64,
    md_index_bottomup UInt64,
    prime_product_smali UInt64,              -- Dalvik semantic primes (analog: prime_product_llil)

    -- Tier 2: Fuzzy matching
    cfg_feature_tlsh Nullable(FixedString(72)),
    wl_minhash Array(UInt8),

    -- Embedding-ready storage
    bb_features Array(Array(UInt16)),        -- ACFG block feature vectors
    cfg_adjacency Array(UInt32),             -- Packed (src << 16 | tgt)

    analysis_date DateTime64(3, 'UTC'),

    -- Indexes
    INDEX idx_topology cfg_topology_hash TYPE bloom_filter GRANULARITY 1,
    INDEX idx_complexity cyclomatic_complexity TYPE minmax GRANULARITY 4,
    INDEX idx_block_count block_count TYPE minmax GRANULARITY 4,
    INDEX idx_edge_count edge_count TYPE minmax GRANULARITY 4,
    INDEX idx_call_count call_count TYPE minmax GRANULARITY 4,
    INDEX idx_cfg_instr_count cfg_instructions_count TYPE minmax GRANULARITY 4,
    INDEX idx_loop_count loop_count TYPE minmax GRANULARITY 4,
    INDEX idx_max_depth max_depth TYPE minmax GRANULARITY 4,
    INDEX idx_max_fan_out max_fan_out TYPE minmax GRANULARITY 4,
    INDEX idx_md_topdown md_index_topdown TYPE minmax GRANULARITY 4,
    INDEX idx_md_bottomup md_index_bottomup TYPE minmax GRANULARITY 4,
    INDEX idx_prime prime_product_smali TYPE bloom_filter GRANULARITY 1,
    INDEX idx_cfg_tlsh cfg_feature_tlsh TYPE bloom_filter GRANULARITY 1
) ENGINE = ReplacingMergeTree(analysis_date)
ORDER BY smali_method_hash;
```

**Column mapping (APK → Binja):**

| APK column | Binja column | Notes |
|------------|-------------|-------|
| `smali_method_hash` | `disassembled_function_hash` | Both SHA-256 of normalized code |
| `cfg_instructions_count` | `llil_total_operations` | Dalvik instructions vs LLIL operations |
| `prime_product_smali` | `prime_product_llil` | Same prime algorithm, Dalvik semantic categories |
| All others | Same name | Identical algorithms from shared `cfg_features.py` |

## Table 7: `code_binja_strings_raw` (shared)

APK strings are inserted into the existing `code_binja_strings_raw` Null-engine table,
which feeds materialized views (`code_binja_strings_by_binary`, `mv_string_popularity_public`).
This enables cross-format string correlation between PE/ELF/Mach-O/APK samples.

No new table creation needed — see `docs/new-code-binja-schema.md` for the existing DDL.

## Table 8: `code_apk_analysis_errors`

**Analog:** `function_analysis_errors_binja`

```sql
CREATE TABLE IF NOT EXISTS code_apk_analysis_errors (
    sha256 FixedString(64),
    class_name Nullable(String) CODEC(ZSTD(3)),
    method_name Nullable(String) CODEC(ZSTD(3)),
    error_location LowCardinality(String) CODEC(ZSTD(3)),   -- 'jadx', 'apktool', 'androguard', 'analysis'
    error_message Nullable(String) CODEC(ZSTD(3)),
    error_type Nullable(String) CODEC(ZSTD(3)),
    error_hash FixedString(32),                               -- MD5 for dedup
    status Enum8('new' = 1, 'investigating' = 2, 'fixed' = 3, 'wontfix' = 4) DEFAULT 'new',
    analysis_date DateTime64(3, 'UTC')
) ENGINE = MergeTree()
ORDER BY (sha256, error_location, error_hash);
```