#ifndef SPX_PARAMS_H #define SPX_PARAMS_H /* Hash output length in bytes. */ #define SPX_N 32 /* Height of the hypertree. */ #define SPX_FULL_HEIGHT 64 /* Number of subtree layer. */ #define SPX_D 8 /* FORS tree dimensions. */ #define SPX_FORS_HEIGHT 14 #define SPX_FORS_TREES 22 /* Winternitz parameter, */ #define SPX_WOTS_W 16 /* The hash function is defined by linking a different hash.c file, as opposed to setting a #define constant. */ /* For clarity */ #define SPX_ADDR_BYTES 32 /* WOTS parameters. */ #define SPX_WOTS_LOGW 4 #define SPX_WOTS_LEN1 (8 * SPX_N / SPX_WOTS_LOGW) /* SPX_WOTS_LEN2 is floor(log(len_1 * (w - 1)) / log(w)) + 1; we precompute */ #define SPX_WOTS_LEN2 3 #define SPX_WOTS_LEN (SPX_WOTS_LEN1 + SPX_WOTS_LEN2) #define SPX_WOTS_BYTES (SPX_WOTS_LEN * SPX_N) #define SPX_WOTS_PK_BYTES SPX_WOTS_BYTES /* Subtree size. */ #define SPX_TREE_HEIGHT (SPX_FULL_HEIGHT / SPX_D) /* FORS parameters. */ #define SPX_FORS_MSG_BYTES ((SPX_FORS_HEIGHT * SPX_FORS_TREES + 7) / 8) #define SPX_FORS_BYTES ((SPX_FORS_HEIGHT + 1) * SPX_FORS_TREES * SPX_N) #define SPX_FORS_PK_BYTES SPX_N /* Resulting SPX sizes. */ #define SPX_BYTES (SPX_N + SPX_FORS_BYTES + SPX_D * SPX_WOTS_BYTES +\ SPX_FULL_HEIGHT * SPX_N) #define SPX_PK_BYTES (2 * SPX_N) #define SPX_SK_BYTES (2 * SPX_N + SPX_PK_BYTES) /* Optionally, signing can be made non-deterministic using optrand. This can help counter side-channel attacks that would benefit from getting a large number of traces when the signer uses the same nodes. */ #define SPX_OPTRAND_BYTES 32 #endif