list SEEDSET = ["", 0];
string SEED_SALT;
integer SEED_ROUNDS=1024;

GENERATE_SEED(string seed, string salt, integer rounds) {
    SEEDSET = [STRETCH_KEY(seed, salt, rounds), 0];
}

integer PRAND() {
    integer index = llList2Integer(SEEDSET, 1);
    string hash = llList2String(SEEDSET, 0);
    if(index > 7) {
        GENERATE_SEED(hash, SEED_SALT, SEED_ROUNDS);
        return PRAND();
    }
    SEEDSET = [hash, index+1];
    return (integer)("0x"+llGetSubString(hash, index*8, ((index+1)*8)-1));
}

string STRETCH_KEY(string input, string salt, integer rounds) {
    string hash = "";
    for(rounds=rounds; rounds>=0; rounds--) {
        hash = iwSHA256String(hash + input + salt);
    }
    return hash;
}