AES modes
In cryptographic terms, a "mode" is used to change the behaviour of the underlying
block cipher (in this case AES), so that it has more useful properties. Modes are
therefore a powerful way to enhance security, alter the behaviour of encryption
in the face of data errors, or provide authentication instead of (or in addition
to) encryption.
If you are not familiar with the concept of block cipher modes,
please take a look at our AES modes backgrounder page
where we explain all this in more detail.
Mode support in Helion AES cores
Helion AES cores are designed to support any mode or combination of modes.
Some of the most popular modes are listed in the table below, but if you are
looking for a mode not mentioned here, please contact us for more information.
| MODE |
Name of mode |
Encryption |
Authentication |
|
| ECB |
Electronic Code Book |
 |
|
 |
| CBC |
Cipher Block Chaining |
|
|
|
| CFB |
Cipher FeedBack |
|
|
|
| OFB |
Output FeedBack |
|
|
|
| CTR |
Counter Mode |
|
|
|
| XTS |
AES-XTS (XEX) Tweakable Blk Cipher |
|
|
|
| CCM |
Counter with CBC-MAC |
|
|
|
| GCM |
Galois Counter Mode |
|
|
|
| XCBC |
eXtended CBC-MAC |
|
|
|
| CMAC |
One-key MAC (aka OMAC) |
|
|
|
Helion also offers support for multiple modes which can be dynamically selected, for occasions
where more than one protocol must be supported. Please contact Helion for more information.
Key wrapping, where a session key is protected by encryption for
transfer or storage, is also easily implemented using Helion's AES solutions. Ready made
solutions are available using the NIST and ANS standard algorithms. Please see our specific
Key wrap page for full details.
For complete flexibility, Helion has an AES Processor core which
includes a powerful programmable datapath capable of implementing any combination of the common
block cipher modes plus many of the newer enhanced modes of AES. This solution is particularly
useful when committing to ASIC silicon ahead of knowing what mode you need to implement.
In this case, the AES Processor core then gives you full programmability in the field, plus support
for almost any mode, including the more advanced combined encryption and authentication modes like
CCM. See our AES Processor page for more information.
Contact
For more detailed information on this or any of our other products and services,
please feel free to email us at
helioncores@heliontech.com and we will be pleased to discuss how we can assist
with your individual requirements.
|
