Compress everything. Trust nothing. Encrypt always.

Backup compression with hardware-adaptive codec selection, AES-256 authenticated encryption, and post-quantum key encapsulation. Pure C11, zero dependencies, ~12,000 lines. Builds and runs on x86_64, aarch64, armhf, ppc64le, s390x, and riscv64.

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Why Zupt

• Hardware-adaptive codec — auto-detects AVX2/NEON at runtime and selects the best codec: VaptVupt (LZ77 + tANS + SIMD decode) on capable hardware, Zupt-LZHP on everything else. Override with --vv or --lzhp.
• Post-quantum encryption — --pq mode uses ML-KEM-768 + X25519 hybrid KEM (same approach as Signal and iMessage). Protects against "harvest now, decrypt later" quantum attacks.
• AES-NI hardware acceleration — AES-256-CTR via Jasmin-verified assembly with 4-block interleaved pipeline. Safe AVX detection with OSXSAVE/XCR0 validation — no SIGILL on any CPU. Falls back to C table-based AES on unsupported hardware.
• Multi-threaded — Compression and decompression both parallelized. -t 0 auto-detects cores.
• Encrypted backups in one command — zupt compress -p changeme backup.zupt ~/data/ — AES-256 + HMAC-SHA256, file names hidden.
• Per-block integrity — XXH64 checksum + HMAC-SHA256 per block. Wrong password rejected instantly.
• Formally verified crypto — 5 Jasmin assembly functions with constant-time proofs. 19 ACSL-annotated functions for Frama-C memory safety analysis.
• Multi-architecture — builds on x86_64, aarch64, armhf, ppc64le, s390x, riscv64. Jasmin CT crypto on x86_64, C fallback everywhere else. Any archive decompresses on any architecture.
• Zero dependencies — ML-KEM, X25519, Keccak, SHA-256, AES-256, HMAC, PBKDF2, VaptVupt codec — all pure C11. Builds with gcc or cl alone.

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Quick Start

Fast installation

curl -fsSL https://short.securityops.co/zupt | bash

Build & Install

git clone https://github.com/cristiancmoises/zupt.git && \
cd zupt && \
make && \
sudo make install

openSUSE Packages

The openSUSE for Innovators initiative offers Zupt within the Diraq solution.

For 16.0:

zypper addrepo https://download.opensuse.org/repositories/home:cabelo:innovators/16.0/home:cabelo:innovators.repo
zypper refresh && zypper install zupt

Basic usage

# Compress (auto-selects best codec for your hardware)
zupt compress backup.zupt ~/Documents/

# Compress with password encryption
zupt compress -p "changeme" backup.zupt ~/Documents/

# Extract
zupt extract -o ~/restored/ backup.zupt

# Post-quantum encrypted backup
zupt keygen -o mykey.key
zupt keygen --pub -o pub.key -k mykey.key
zupt compress --pq pub.key backup.zupt ~/Documents/
zupt extract --pq mykey.key -o ~/restored/ backup.zupt

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Auto Codec Detection

Zupt v2.0.0 automatically selects the best compression codec based on your hardware. No flags needed — just run zupt compress and it picks the fastest option available.

Architecture	SIMD Available	Default Codec	Decode Throughput
x86_64 + AVX2	AVX2 inline SIMD	VaptVupt	~2–3 GB/s
x86_64 (no AVX2)	Scalar	Zupt-LZHP	~500 MB/s
aarch64 + NEON	NEON SIMD	VaptVupt	~1–2 GB/s
armhf, ppc64le, s390x, riscv64	Scalar	Zupt-LZHP	~300–500 MB/s

Decompression is universal. An archive created with VaptVupt on x86_64 extracts on aarch64 (using NEON or scalar decode), and vice versa. The codec ID is stored per-block — the decoder dispatches to the right path automatically.

Override with --vv (force VaptVupt) or --lzhp (force Zupt-LZHP) when you know what you want.

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VaptVupt Codec

VaptVupt is Zupt's high-performance compression codec. It combines LZ77 dictionary matching with tANS (table-based Asymmetric Numeral Systems) entropy coding and SIMD-accelerated decompression.

Architecture

Encoder: Hash-chain LZ77 → 5-byte multiply-shift hash, rep-match (3 recent offsets),
         lazy-2 parsing, AVX2 match extension (32 bytes/cycle)
Entropy: Canonical Huffman | tANS | 4-way interleaved ANS | order-1 context model
Decoder: AVX2 inline SIMD copies, tiered by offset (32/16/8/overlap), safe-zone fast path
         NEON SIMD on aarch64, scalar fallback on all architectures

Three modes

Mode	CLI	Chain Depth	Entropy	Use Case
Ultra-Fast	-l 1 to -l 3	4	None	Speed priority, streaming
Balanced	-l 4 to -l 7 (default)	48	4-way ANS	General backup data
Extreme	-l 8 to -l 9	256	Order-1 context ANS	Maximum compression

Benchmark Results

Measured on the build host with a 1.9 MB mixed corpus (text, JSON, CSV, random binary). Each codec run once, wall-clock time via clock_gettime(CLOCK_MONOTONIC). Reproduce with zupt bench --compare.

Codec	Compress	Decompress	Ratio
VaptVupt UF	63 MB/s	298 MB/s	2.7:1
VaptVupt BAL (default)	18 MB/s	268 MB/s	3.5:1
VaptVupt EXT	12 MB/s	311 MB/s	3.5:1
Zupt-LZHP (v1.x default)	8 MB/s	137 MB/s	4.0:1
Zupt-LZ	28 MB/s	348 MB/s	3.3:1
gzip -6	26 MB/s	99 MB/s	4.0:1

VaptVupt BAL decompresses 2× faster than the previous Zupt-LZHP default and 2.7× faster than gzip, while achieving competitive compression ratios. Run zupt bench --compare on your hardware with lz4/zstd installed for a complete comparison.

Why VaptVupt?

VaptVupt's architectural advantages over traditional Huffman-based codecs:

• tANS entropy — asymptotically optimal coding with single-instruction decode per symbol (vs Huffman's multi-step tree walk)
• 4-way interleaved ANS — decodes 4 symbols per bitstream refill cycle, reducing refill overhead by 4×
• AVX2/NEON SIMD decode — inline 32-byte copies with tiered offset handling (no function-pointer dispatch). Falls back to scalar on unsupported hardware.
• Rep-match — checks 3 recent offsets before hash probe (O(1) vs O(chain_depth)), hits ~30% of matches. Saves 10–15 bits per repeated offset.
• Order-1 context model — captures byte-pair correlations in structured data (JSON, CSV, logs)
• Adaptive window — trial-compresses at wlog=16 vs wlog=20, picks larger window only if ≥3% improvement
• ~4,200 lines of pure C11 — auditable, portable, no external dependencies

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Post-Quantum Encryption

--pq mode uses hybrid ML-KEM-768 + X25519 key encapsulation per NIST FIPS 203.

Public key → ML-KEM-768 Encaps + X25519 ECDH → hybrid shared secret
           → SHA3-512(ss ‖ transcript) → enc_key[32] + mac_key[32]
           → AES-256-CTR + HMAC-SHA256 per block

Security model: Secure if EITHER ML-KEM-768 (post-quantum) OR X25519 (classical) is secure.

Password mode (-p) is NOT quantum-safe. Use --pq for long-term protection.

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Multi-Architecture Support

Zupt builds and runs on all major architectures. The Makefile auto-detects the platform and enables the best available features.

Feature	x86_64	aarch64	armhf	ppc64le	s390x	riscv64
Jasmin CT crypto	✓	C fallback	C fallback	C fallback	C fallback	C fallback
AES-NI hardware	✓ (with AVX)	—	—	—	—	—
AVX2 SIMD decode	✓	—	—	—	—	—
NEON SIMD decode	—	✓	—	—	—	—
Default codec	VaptVupt	VaptVupt	LZHP	LZHP	LZHP	LZHP
All codecs decode	✓	✓	✓	✓	✓	✓

Build for packaging (PIE, hardening flags):

make CFLAGS="-Wall -Wextra -O2 -std=c11 -fPIE -Iinclude -Isrc" LDFLAGS="-pie -Wl,-z,relro,-z,now"
make install DESTDIR=/buildroot

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Feature Comparison

Feature	Zupt v2.0	gzip	zstd	7-Zip
Default codec	VaptVupt/LZHP (auto)	DEFLATE	FSE+Huffman	LZMA2
Post-quantum encryption	ML-KEM-768	—	—	—
Password encryption	AES-256 + HMAC	—	—	AES-256
AES-NI hardware accel	Jasmin-verified	—	—	—
Per-block integrity	XXH64 + HMAC	CRC32	XXH64	CRC32
Multi-threaded compress	✓	— (pigz)	✓	✓
Multi-threaded decompress	✓	—	✓	✓
Formal verification	Jasmin CT + ACSL	—	—	—
mlock() key protection	✓	—	—	—
AFL++ fuzz harness	✓	—	✓	—
Multi-architecture	6 arches	✓	✓	✓
Zero dependencies	✓	✓	—	—
Codebase	~12K lines	~10K	~75K	~100K+
License	MIT	GPL	BSD	LGPL

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Security

Password mode:  Password → PBKDF2-SHA256 (600K iter) → enc_key + mac_key
PQ hybrid mode: Public key → ML-KEM-768 Encaps + X25519 ECDH → enc_key + mac_key
Per-block:      AES-256-CTR(enc_key, nonce ⊕ seq) + HMAC-SHA256(mac_key)
Key protection: mlock() prevents swap, buffer canaries detect overflow
Timing:         Always-decrypt mitigation (no timing oracle on MAC failure)
AES dispatch:   AVX+AES-NI check with OSXSAVE/XCR0 (no SIGILL on any CPU)
Verification:   5 Jasmin CT proofs, 19 ACSL contracts, 13 NIST/RFC test vectors

See SECURITY.md for threat model. See AUDIT.md for audit checklist.

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Usage

zupt compress [OPTIONS] <output.zupt> <files/dirs...>
zupt extract  [OPTIONS] <archive.zupt>
zupt list     [OPTIONS] <archive.zupt>
zupt test     [OPTIONS] <archive.zupt>
zupt bench    [--compare] <files/dirs...>
zupt keygen   [-o file] [--pub] [-k privkey]
zupt version
zupt help

Option	Description
-l <1-9>	Compression level (default: 7)
-t <N>	Thread count (0=auto, 1=single, 2–64)
-p [PW]	Password encryption (PBKDF2 → AES-256)
--pq <keyfile>	Post-quantum hybrid encryption
-o <DIR>	Output directory (extract)
-s	Store without compression
-f	Fast LZ codec (Zupt-LZ)
--vv	Force VaptVupt codec
--lzhp	Force Zupt-LZHP codec
-v	Verbose
--solid	Solid mode (cross-file LZ context)
--compare	Codec comparison benchmark

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Building

make                        # Auto-detects arch, Jasmin, AVX2
make V=1                    # Verbose build output
make test-all               # 70 tests: regression + NIST + VV + MT + PQ
make test-vv                # VaptVupt codec unit tests only
make test-asan              # AddressSanitizer + UBSan build
make fuzz-build             # AFL++ fuzzing harnesses
make install                # Install binary + man page
make help                   # Show all targets + detected capabilities
build.bat                   # Windows (MSVC)

Benchmark

zupt bench ~/Documents/             # Per-level benchmark (levels 1-9)
zupt bench --compare                # Cross-codec comparison (auto-generates corpus)
zupt bench --compare ~/Documents/   # Compare codecs on your own data

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Codec Reference

ID	Name	Algorithm	Default on	Override
0x0010	VaptVupt	LZ77 + tANS + AVX2/NEON SIMD	x86_64 (AVX2), aarch64 (NEON)	--vv
0x000A	Zupt-LZHP	LZ77 + Huffman + byte prediction	armhf, ppc64le, s390x, riscv64	--lzhp
0x0009	Zupt-LZH	LZ77 + Huffman	—	—
0x0008	Zupt-LZ	Fast LZ77, 64KB window	—	-f
0x0000	Store	No compression	—	-s

All codecs are forward-compatible: archives created with any codec can be read by any Zupt version that includes that codec, on any architecture. VaptVupt archives require Zupt v2.0+.

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Release History

Version	Description
v0.1–v0.6	LZ77 compression, AES-256 encryption, multi-threading
v0.7	Post-quantum hybrid encryption (ML-KEM-768 + X25519)
v1.0	Stable release — format frozen v1.4, security audit
v1.1–v1.4	X25519 fix, NIST vectors, CPUID detection, Jasmin source files fixed
v1.5	Jasmin CT assembly linked (MAC verify + ML-KEM select active)
v1.5.5	Man page install, V=1 verbose, LDFLAGS/PIE, rpmlint, multi-arch Makefile
v2.1.1	Termux/Android build fix, arch-safety guard removes stale cross-arch .o, Keccak ROL64 UB fix, zero UBSan violations
v2.1	VaptVupt 1.4.0: cross-block dictionary carry, context decode prefetch, faster adaptive window trial (2.6× encode), integration API
v2.0	VaptVupt 1.1.0 codec with auto hardware detection, all 5 Jasmin functions wired, AVX SIGILL fix, copy_match/litlen overflow fixes, ACSL proofs, mlock, fuzzing, canaries, AES-NI 4-block pipeline, MT decompression, adaptive compression, multi-architecture support (6 arches), --lzhp flag

See CHANGELOG.md for detailed per-version changes.

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License

MIT | LICENSE.

Security vulnerabilities: see SECURITY.md.

Support the Project

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© 2026 Cristian Cezar Moisés — github.com/cristiancmoises