Greg,

you've got the point.

My question was about performance and, depending on what we ask the z12, it
will answer.

So if I ask for a CSNBKEX API (and now I discovered it was clearly written
in the manual) z12 have to use CEX3/4 Coprocessor.

Finally I've found the answer to my main question about the performance (in
terms of crypto/second) per single server (where server is the single
mono-tcb address space calling the API services).

Then, as long as I need CEX3/4 API I have to pay the 1ms elapsed time per
call because there's the need to raise the "not so close" hardware.

I really thank all of you for your valuable support and knowledge. I've
learnt lots of new stuffs.

Best regards.
Massimo


2013/5/21 Greg Boyd <[email protected]>

> I'm not sure I understand your last question ... but let me try to clarify
> a couple of things.
>
> It's important to realize that you have two separate pieces of crypto
> hardware available on System z:
> the CPACF for symmetric clear key and hashing operations and
> the Crypto Express card for symmetric secure key, MAC, public/private key
> operations, Financial/PIN operations, etc.
>
> There is really no overlap in functionality between the two devices.  Both
> can do symmetric DES/TDES or AES encryption, but the CPACF does the work
> with a clear key, while the CEX card uses a secure key.
>
> So that means the hardware you need depends entirely on which API you
> specify in your code.  In the ICSF Application Programmer's Guide
> (SA22-7522), each API is documented and includes a 'Required Hardware'
> table at the end of each section.  That table will tell you which piece of
> hardware is required for that API (even down to certain parms require
> certain levels of CCA code in the card).
>
> If you code CSNBKEX, the Usage Table for that API says that you must have
> a CEX3 or CEX4 Coprocessor on your zEC12 to use that API.
>
> One note about Protected Key.  To use Protected Key, you use a clear key
> API, but pass a secure key to the API.  Prior to the implementation of
> protected key, this would fail as the clear key APIs can't use a secure
> key.  However, with the protected key support, ICSF will recognize this
> combination and allow the operation to proceed.  In this case, ICSF uses
> both the Crypto Express card to decrypt the operational key from under the
> master key and the CPACF to rewrap the key and then perform the encrypt or
> decrypt of your data (as Todd described).  The 'Required Hardware' table
> refers to protected keys as 'Encrypted Keys'.  So if you want to simply do
> clear key encryption, you only require the CPACF hardware.  But if you want
> to use protected key, then you must also have a Crypto Express card
> (configured as a coprocessor).
>
> So, in your example, if you use the CSNBKEX API, that implies you have a
> CEX card because that's where the work will be routed.  And if you use the
> CSNBSYE API, you want to use the CPACF hardware.
>
> You might want to review the 'A Synopsis of Systme z Crypto Hardware'
> Techdoc, available at
> http://www.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/WP100810  .
>
> I hope that helps clarify things.
> Greg Boyd
> IBM Advanced Technical Support
> Supporting Crypto on System z
>
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