Digital Signing guidelines - NatWest

4. Use of File Signing
4.1 Typical Use of an HSM
A Hardware Security Module (HSM) can be used to apply a digital signature to a payment file before it is sent onto
the Bankline Direct service. The HSM stores the certificates and signing keys.
A typical use of an HSM solution is for a payment file to be generated and presented to the HSM in order to apply
a digital signature automatically to the file before being sent to the Bankline Direct service.
HSMs also have the capability to store the Bankline Direct certificate details to validate files being sent to the
customer from the service.
Please refer to section 7 for configuration details for HSM.
4.2 Typical Use of Smartcards
Smartcards and card readers provide a manual approach to apply digital signatures to payment files. The card
readers are connected to a local computer using specific signing software. Smartcards are assigned to individuals
and must be combined with a user passcode to sanction the digital signing.
A typical use of a Smartcard solution is for a payment file to be generated and presented to the signing software,
where the operator can sign the file (using the eSigner software provided) using their individual Smartcard and
passcode before they submit the files onto the Bankline Direct service.
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