Systems, methods, and apparatus are provided for securing transmission of sensitive data on an LPWAN network such as LoRaWAN. Long-range, low-power transmission may enable a transaction card to communicate with a financial institution server without internet or cellular connectivity. The transaction card may generate a first security key. The key may include a transaction timestamp, a random number generated by the transaction card microprocessor, a personal identifier received at the transaction card from a user, one or more card parameters, and/or any suitable factors. A long-range, low-power network server may detect the card transmission. The server may retrieve the card parameters and personal identifiers stored in association with a user account during card registration. The server may generate a second security key. Based on a match between the first security key and the second security key, the server may authenticate the transmission.