KG_USAGE_SEAL
code = kg_encrypt(context, enc, KG_USAGE_SEAL, NULL, plain,
ctx->enc, KG_USAGE_SEAL, NULL,
ctx->enc, KG_USAGE_SEAL, NULL,
ret = kg_decrypt(context, key, KG_USAGE_SEAL, NULL, in, plain, len);
code = kg_encrypt(context, rkey, KG_USAGE_SEAL, NULL, zeros, seed, 16);