Salto Smart & Construction Cards Explained: 2K/4K, Setup

A Salto smart card is an AES-secured 13.56 MHz contactless smart card, commonly a 2K or 4K memory card, that stores SALTO Space SVN access rights inside encrypted sectors. Salto's XS4 lock platform reads and writes these cards, and the credential is protected by AES-128 mutual authentication so access data cannot be read or altered by an unauthorised encoder.

Unlike a plain proximity card that broadcasts a fixed number, a Salto smart card only releases its data after a two-way cryptographic handshake with a keyed reader. That is why Salto issues the AES-secured smart card for new XS4 and SALTO Space installations, and why the card can safely carry live SVN permissions rather than just an identifier.

A Salto construction card is a temporary credential that operates XS4 locks during the construction or fit-out phase of a building, before the access-control system is commissioned onto its live, site-specific keys. It lets trades and site staff open doors on a new install without issuing full user credentials, keeping a building operable while it is still being finished.

The construction card is intentionally a short-lived tool. It exists so that a half-built site is not locked down before its management software, encoders, and user database are in place. Anyone planning a Salto rollout should budget construction cards as disposable install stock, not as a credential the occupied building will keep using.

Moving from construction cards to live credentials happens at commissioning. When the SALTO Space (or SALTO KS) system is set up with its site keys, encoders, and user records, the locks are brought onto the operational key set and the temporary construction credential stops being valid. Users are then enrolled onto their permanent AES-secured smart cards or mobile keys.

This cutover is the moment a Salto site becomes secure in the full sense: until commissioning, a construction card is a convenience credential, not a hardened one. Retiring construction cards and confirming that every lock is on the live key set is a step worth verifying with the integrator, because a construction card left active after go-live is an open door in the literal sense.

The choice between a 2K and a 4K Salto smart card comes down to how much the card must carry. A 2K card holds enough SVN data for straightforward access control on most sites. A 4K card carries more on-card storage, which matters where a site needs longer audit trails, more doors, or additional applications sharing the card alongside Salto access.

Because SVN writes real permission and blacklist data onto the card, memory headroom affects how much history and how many entitlements a card can hold before it is refreshed at a wall reader. For large estates or multi-application deployments, the 4K card is the safer default; for simple door access, a 2K card is typically sufficient. An integrator sizes this to the specific installation.

The table contrasts a Salto construction card with a permanent AES-secured working credential.

A functioning Salto AES-secured smart card is encoded with your system's own SVN keys, held by SALTO Space or SALTO KS and your integrator, so an independent manufacturer cannot produce a keyed, ready-to-use Salto smart card. Security ID Systems does not sell one, and working encoded credentials and construction cards come through Salto or your integrator.

What we do supply are the blank and open formats around a Salto install — SVN card blanks for enrollment stock, and open serial-number cards for adjacent readers. Those are the formats below.