Slot Number
Slot Use-case
Description
Slot Property
Slot 0
Primary private key
Primary authentication key
Permanent, Ext Sign, ECDH
SLOT 0
Slot Description:
It's permanent to support a "factory reset" option where the
original credentials are always available. It also prevents
Denial-Of-Service attacks where the key is changed, either
intentionally or by accident.
Provisioning:
Private key is generated and locked, no further
modifications can be made to the slot.
Slot 1
Internal sign private key
Private key that can only be used to attest internal keys and state
of the device. Can't be used to sign arbitrary messages.
Permanent, Int Sign
SLOT 1
Slot Description:
The internal sign key can support key attestation (proving a
key is securely held in the ATECC608) during key rotation
operations with the secondary private keys.
Provisioning:
Private key is generated and locked, no further
modifications can be made to the slot. This slot can be used
only for internal sign operation.
Slot 2
Secondary private key 1
Secondary private key for other uses
Updatable, Ext Sign, ECDH, Lockable
SLOT 2
Slot Description:
These keys don't have a specified purpose, but allow
authentication with additional systems using separate keys.
The keys can be changed if needed or locked if the user
wants them permanent. If the keys are changed, key
attestation can performed with the Internal signer private
key to prove the new key is in the ATECC608, if required.
Provisioning:
This private key can be updated internally using the GenKey
command. Data to this slot is genererated internally, slot
data is not user writable.
Disable slot write:
If the following checkbox is checked, the contents of
the slot cannot be modified under any
circumstances.
Slot 3
Secondary private key 2
Secondary private key for other uses
Updatable, Ext Sign, ECDH, Lockable
SLOT 3
Slot Description:
These keys don't have a specified purpose, but allow
authentication with additional systems using separate keys.
The keys can be changed if needed or locked if the user
wants them permanent. If the keys are changed, key
attestation can performed with the Internal signer private
key to prove the new key is in the ATECC608, if required.
Provisioning:
This private key can be updated internally using the GenKey
command. Data to this slot is genererated internally, slot
data is not user writable.
Disable slot write:
If the following checkbox is checked, the contents of
the slot cannot be modified under any
circumstances.
Slot 4
Secondary private key 3
Secondary private key for other uses
Updatable, Ext Sign, ECDH, Lockable
SLOT 4
Slot Description:
These keys don't have a specified purpose, but allow
authentication with additional systems using separate keys.
The keys can be changed if needed or locked if the user
wants them permanent. If the keys are changed, key
attestation can performed with the Internal signer private
key to prove the new key is in the ATECC608, if required.
Provisioning:
This private key can be updated internally using the GenKey
command. Data to this slot is genererated internally, slot
data is not user writable.
Disable slot write:
If the following checkbox is checked, the contents of
the slot cannot be modified under any
circumstances.
Slot 5
Secret key
Storage for a secret key
No read, Encrypted write(6), Lockable,
AES key
Slot 6
IO protection key
Key used to protect the I2C bus communication (IO) of certain
commands. Requires setup before use.
No read, Clear write, Lockable
Slot 7
Secure Boot digest
Storage location for Secure Boot digest. This is an internal
function, so no reads or writes are enabled.
No read, No write
SLOT 7
Slot Description:
This slot is used as a secure location to store the
Secure Boot digest. This slot can be updated only through
internal commands so no external read/write is possible on
this slot.
Provisioning:
No external writes are allowed to this slot, data can be
stored only using internal commands. This slot is not user
writable.
Slot 8
General data
General public data storage (416 bytes)
Clear read, Always write, Lockable
Slot 9
AES key
Intermediate key storage for ECDH and KDF output
No read, Always write, AES key
Slot 10
Device compressed certificate
Certificate primary public key in the Crypto Authentication
compressed format
Clear read, No write
SLOT 10
Slot Description:
Device compressed certificate is stored in this slot. This
slot is written with certificate signed by Microchip signers
and root.
It's permanent to support a "factory
reset" option where the original credentials are always
available. It also prevents Denial-Of-Service attacks where
the cert is changed, either intentionally or by accident.
Provisioning:
The slot is provisioned by Microchip with its owm root and
signers. There are two options that customers can choose
from(Microchip Standard Certificate or Custom certificate).
Microchip standard certificate: Certificate
elements like
name, date, country....... will be filled by
Microchip.
The certificate will be signed with Microchip
signers.
Custom Certificate: This option will allow the
Customer
to define some of the certificate elements like
name and
data.
Select device certificate type:
Microchip Standard Certificate
Custom Certificate
Notes on Custom Device Certificate
Due to the way the certificates
are stored/retrieved from the ECC608 device, using
Custom certificates will require some knowledge on
compressed certificates and certificate templates.
The issue date only has a resolution of hours.
Minutes and seconds are assumed to be zero.
Refer to Compressed Certificate
Definition for further details on the
compressed certificates.
The custom definition files (.c, .h) being generated
assumes the size of Organization and Common Names
matches with MCHP standard certificates.
The Distinguished Names, both for the Issuer and for
the Subject in all certificates must be comprised of
an Organization Name and a Common Name entry, in
that order.
The Organization Name entered here gets padded and
spaces replaced with '_' to match with MCHP standard
certificates sizes.
It is recommended to use default CommonName i.e.
device serial prefixed with sn. If this needs to be
different, its size would be matched to MCHP
standard certificates with spaces replaced by '_'
For the Device certificate Basic Constraints come
before the Key Usage, following is the order of
extensions:
Basic Constraints: critical, CA:FALSE
Key Usage: critical Digital Signature, Key
Agreement
Subject Key Identifier
Authority Key Identifier
Populate below to customize certificate fields:
Use default CN
i.e. Serial Number
Use Avnet
Prefix
Slot 11
Signer public key
Public key for the CA (signer) that signed the device cert
Clear read, No write
SLOT 11
Slot Description:
Signer public key is stored in this slot. It's
permanent to support a "factory reset" option where the
original credentials are always available. It also prevents
Denial-Of-Service attacks where the cert is changed, either
intentionally or by accident.
Provisioning:
The slot is provisioned by Microchip with the signer public
key. Slot data is not user modifiable.
Slot 12
Signer compressed certificate
Certificate for the CA (signer) certificate for the device
certificate in the CryptoAuthentication compressed format
Clear read, No write
SLOT 12
Slot Description:
Signer compressed certificate is stored in this slot.
It's permanent to support a "factory reset"
option where the original credentials are always available.
It also prevents Denial-Of-Service attacks where the cert is
changed, either intentionally or by accident.
Provisioning:
The slot is provisioned by Microchip's root key. There are
two options that customers can choose from(Microchip
Standard Certificate or Custom certificate).
Microchip standard certificate: Certificate
elements like
name, date, country....... will be filled by
Microchip.
The certificate will be signed with Microchip
root.
Custom Certificate: This option will allow the
Customer
to define some of the certificate elements like
name and
data.
Select certificate type:
Microchip Standard
Certificate
Custom
Certificate
Notes on Custom Signer Certificate:
Due to the way the certificates
are stored/retrieved from the ECC608 device, using
Custom certificates will require some knowledge on
compressed certificates and certificate templates.
The issue date only has a resolution of hours.
Minutes and seconds are assumed to be zero.
Refer to Compressed Certificate
Definition for further details on the
compressed certificates.
The custom definition files (.c, .h) being generated
assumes the length of Organization and Common Names
matches with MCHP standard certificates.
The Distinguished Names, both for the Issuer and for
the Subject in all certificates must be comprised of
an Organization Name and a Common Name entry, in
that order
The Organization Name entered here gets padded and
spaces replaced with '_' to match MCHP standard
certificates sizes.
The Subject Common Name in the Signer certificate
resp. the Issuer Common Name in the Device
certificate gets padded and spaces replaced with '_'
to match MCHP standard certificates sizes.
The Signer certificates must contain exactly the
following extensions in exactly the same order:
Key Usage, critical: Digital Signature,
Certificate Sign, CRL Sign
Basic Constraints, critical: CA: TRUE,
PATHLEN: 0
Subject Key Identifier
Authority Key Identifier
Populate below to customize certificate fields:
Slot 13
Parent public key or general data
Parent public key for validating/invalidating the validated public
key. Can also be used just as a public key or general data storage
(72 bytes).
Clear read, Always write, Lockable
Slot 14
Validated public key
Validated public key cannot be used (verify command) or changed
without authorization via the parent public key.
Clear read, Always write, Validated (13)
Slot 15
Secure Boot public key
Secure Boot public key
Clear read, Always write, Lockable