Get signature

Returns the signature on the commands or responses sequence since the latest start of a signature session.

Verify entity signature

Verifies a signature generated by an off-chip entity over a challenge previously generated by the STSAFE-A120

with the generate challenge command.

Decompress public key

Supports the decompression of a NIST or brainpool public key available in compressed form with its X coordinate.

It returns the Y coordinate of the public key.

4.5

Local envelope commands

Generate local envelope key

Generates local envelope key.

Wrap local envelope

This command is used to wrap data with a local key envelope using an AES key wrap algorithm.

Unwrap local envelope

This command is used to unwrap a local envelope with a local envelope key.

4.6

Data-partition commands

Decrement

Decrements the one-way counter in a counter zone. When the counter reaches zero, the command is refused.

Read

Reads data from a data partition zone. It reads the data starting from the specified offset within the zone and with

the requested length. It checks the access conditions (for example the MAC) and only returns the data starting

from the specified offset up to the zone boundary.

This command can also be used to change the read access conditions of the zone to a stricter value.

Update

Updates data in a zone. It checks if the written data is expected to exceed the zone boundary and if so, does not

perform the operation. It also checks whether the access condition is satisfied (for example the MAC) and if not,

does not perform the operation.

This command can also be used to change the update access conditions of the zone to a stricter value.

4.7

Symmetric key table commands

Write symmetric key plaintext

Supports the provisioning of a slot in the symmetric key table with a key in plaintext format

Write symmetric key wrapped

Supports the provisioning of a slot in the symmetric key table with a wrapped key.

Establish symmetric keys

Supports provisioning of new keys in the symmetric key table using the ECDHE protocol.

Confirm symmetric keys

Supports the provisioning and confirmation of new keys in the symmetric key table in combination with the

establish symmetric keys command.

Derive keys

Supports the derivation of one or more output keys from an input key present in the symmetric key table or

passed as a part of the command data.

Erase symmetric key slot

Erases the content of the specified key slot in the symmetric key table. This is required when the slot has been

provisioned with the derive keys command and when the key slot is not locked.

STSAFE-A120

Command sets

DS14609 - Rev 1

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