EP3SE50F780I3N Altera, EP3SE50F780I3N Datasheet - Page 467

• Manufacturer Part Number: EP3SE50F780I3N
• Description: Stratix III
• Manufacturer: Altera

AES Decryption
Block
Flexible Security
Key Storage
Altera Corporation
October 2007
The main purpose of the AES decryption block is to decrypt the
configuration bitstream prior to entering data decompression or
configuration.
Prior to receiving encrypted data, you must enter and store the 256-bit
security key in the device. You can choose between a non-volatile security
key and a volatile security key with battery backup.
The security key is scrambled prior to storing it in the key storage in order
to make it more difficult for anyone to retrieve the stored key via
de-capsulation of the device.
Stratix III devices support two types of security keys programming:
volatile and non-volatile keys.
volatile keys and non-volatile keys.
The non-volatile key can be programmed to the Stratix III device without
an external battery. Also, there are no additional requirements to any of
the Stratix III power supply inputs.
V
shared with other on-chip power supplies, such as V
continuously supplies power to the volatile register regardless of the
on-chip supply condition. The nominal voltage for this supply is 2.5 V,
while its valid operating range is from 1.0 to 3.0 V. If you do not use the
volatile security key, you may connect the V
2.5 V power supply.
Note to
(1)
Key programmability
External battery
Key programming
method
Design protection
Table 14–1. Security Keys Options
CCBAT
Key programming is carried out via JTAG interface.
is a dedicated power supply for the volatile key storage and not
Table
(1)
Options
14–1:
Reprogrammable and
erasable
Required
On-board
Secure against copying
and reverse engineering
Table 14–1
Volatile Key
Stratix III Device Handbook, Volume 1
Design Security in Stratix III Devices
shows the differences between
CCBAT
On and off board
One-time programmable
Not required
Secure against copying,
reverse engineering, and
tampering
to either ground or a
Non-Volatile Key
CCIO
or V
CC
. V
CCBAT
14–3