Package-level declarations

Adler-32 (RFC 1950): the zlib-stream trailer checksum. Two 16-bit rolling sums modulo 65521, combined as (b shl 16) or a. Faster but weaker than CRC-32.

A streaming, unkeyed integrity check (CRC / Adler family). All implementations are pure-Kotlin and table-driven. They are cheap (GB/s), export-safe, and need no constant-time care, so the core module can hold them. AES is different: this design delegates it to a platform crypto provider.

CRC-32 (IEEE 802.3 / zlib / gzip / PNG): reflected polynomial 0xEDB88320, init 0xFFFFFFFF, final XOR 0xFFFFFFFF. Matches zlib's crc32().

CRC-32C (Castagnoli): reflected polynomial 0x82F63B78, init 0xFFFFFFFF, final XOR 0xFFFFFFFF. Used by btrfs/ext4/iSCSI/SCTP and as an optional 7z check (NOT by ZIP, which uses Crc32).

CRC-64/XZ (ECMA-182): reflected polynomial 0xC96C5795D7870F42, init 0xFFFFFFFFFFFFFFFF, final XOR 0xFFFFFFFFFFFFFFFF. This is the integrity check used by the .xz container (and an optional 7z check).

xxHash32 (Yann Collet): the checksum used by the LZ4 frame format for its header (HC byte) and optional block/content checks. Pure-Kotlin, one-shot. 32-bit wrapping arithmetic done in Int; the result is exposed unsigned in the low 32 bits of a Long.