Talking about Cryptodevices... which one?

[Felix E. Klee]

On Tue, Jan 27, 2015 at 5:19 PM, Andreas Schwier
<andreas.schwier.ml at cardcontact.de> wrote:
> The platform we use for the SmartCard-HSM generates a random AES key
> during platform initialization and encrypts all key material in EEPROM
> under this key. The only time the key is handled in plain (plain
> meaning within the protected enclosure of the secure microcontroller)
> is when the crypto unit performs a private key operation.

Good! What PIN length do you recommend? (for the case that there is a
backdoor to get the *encrypted* key off the card)