Security Device in Cash Registers
To protect against tampering, starting 1 April 2017, each cash register must be equipped with a technical security device.
Exact Information on the Security Device
The tamper resistance of recordings is guaranteed by cryptographic changing of every single sale by signatures from signature creation devices with signature certificates assigned to the taxpayer.
The security device consists of a chain of the cash transactions with the aid of the electronic signature of the signature creation unit.
The chain is formed by including elements of the last assigned signature stored in the data collection protocol in the current signature to be created. In the creation of the first cash transaction, the last assigned signature is replaced by the till identification number.
The encrypted signature is part of the machine readable code printed on any receipt (QR-Code).