Scloud+ Minimal Implementation

This branch is a compact implementation package for Scloud+ KEM. It keeps a single public-matrix byte format and only the Reference and Optimized tiers.

Layout

Implementations/
  Reference_Implementation/Scloudplus-{128,192,256,384,512}/kem/
  Optimized_Implementation/Scloudplus-{128,192,256,384,512}/kem/
  _shared/
Self_Evaluation/
Test_Vectors/

All concrete builds use the same public-matrix representation; historical algorithm names and KAT filenames keep the packed10 tag for compatibility with earlier submission material.

Build

Reference example:

cmake -S Implementations/Reference_Implementation/Scloudplus-256/kem \
      -B build/ref-256-sm3 \
      -DCMAKE_BUILD_TYPE=Release \
      -DSCLOUDPLUS_FAMILY=SM3
cmake --build build/ref-256-sm3
./build/ref-256-sm3/test_scloudplus

Optimized x86_64 example:

cmake -S Implementations/Optimized_Implementation/Scloudplus-512/kem \
      -B build/opt-512-shake \
      -DCMAKE_BUILD_TYPE=Release \
      -DSCLOUDPLUS_FAMILY=SHAKE
cmake --build build/opt-512-shake
./build/opt-512-shake/test_scloudplus

Optimized AArch64 example:

cmake -S Implementations/Optimized_Implementation/Scloudplus-512/kem \
      -B build/opt-512-aes \
      -DCMAKE_BUILD_TYPE=Release \
      -DSCLOUDPLUS_FAMILY=AES
cmake --build build/opt-512-aes
./build/opt-512-aes/test_scloudplus

CMake Options

• SCLOUDPLUS_FAMILY: AES, SHAKE, or SM3; defaults to AES.
• SCLOUDPLUS_BACKEND: Optimized tier only, AUTO, AVX2, or NEON; defaults to AUTO.

The Reference tier always uses the portable reference backend. In the Optimized tier, AUTO selects AVX2 on x86_64/AMD64 and NEON on AArch64/ARM64. Set SCLOUDPLUS_BACKEND explicitly only when you need to test one backend deliberately. The public matrix format is fixed and is not a user option.

Direct Compiler Use

CMake is only a convenience wrapper. Each kem/ directory has a checked-in level-specific parameters.h; the shared scloudplus_param_common.h header derives the family/backend-dependent constants from compiler definitions. Embedded projects or Makefiles can compile the same sources directly by passing the family/backend macros. For example, a portable AES-128 correctness build can be compiled with:

cc -std=c99 -O2 \
  -DSCLOUDPLUS_FAMILY_AES -DSCLOUDPLUS_TIER_REFERENCE \
  -DSCLOUDPLUS_REF_FAMILY_AES \
  -I Implementations/Reference_Implementation/Scloudplus-128/kem \
  -I Implementations/_shared/scloudplus_core/include \
  -I Implementations/_shared/api_pkc \
  Implementations/_shared/scloudplus_core/common/aes_reference.c \
  Implementations/_shared/scloudplus_core/common/encode.c \
  Implementations/_shared/scloudplus_core/common/hash_aes_shake.c \
  Implementations/_shared/scloudplus_core/common/kem.c \
  Implementations/_shared/scloudplus_core/ref/matrix_reference.c \
  Implementations/_shared/scloudplus_core/common/pack.c \
  Implementations/_shared/scloudplus_core/common/pke.c \
  Implementations/_shared/scloudplus_core/common/random.c \
  Implementations/_shared/scloudplus_core/common/sample.c \
  Implementations/_shared/scloudplus_core/common/util.c \
  Implementations/Reference_Implementation/Scloudplus-128/kem/KEM_AlgorithmInstance.c \
  Self_Evaluation/tests/test_scloudplus.c \
  -o test_scloudplus

Targets

Each kem/ entry builds:

• test_scloudplus: correctness tests.
• kem_loop_scloudplus: repeated KEM loop smoke test.
• tamper_scloudplus: ciphertext tamper and implicit-rejection test.
• kat_kem_scloudplus: deterministic KAT generator.
• verify_kat_kem: deterministic KAT replay verifier.
• bench_scloudplus: local benchmark entry.
• scloudplus_kem: shared KEM library.

Canonical KAT files are stored in Test_Vectors/.