Smartcards and tokens

[sivmu]

Am 15.12.2016 um 22:17 schrieb Damien Goutte-Gattat:
> On 12/15/2016 08:35 PM, sivmu wrote:
>> From what I understand, a malicious token can e.g. perform encryption
>> operations with weak randomness to create some kind of backdoor that is
>> hard to detect.
> 
> The token is normally not used to perform any *encryption*. You encrypt
> with the public key of your correspondant, which is stored on your
> computer, not on your token (there's no need to protect it since it is a
> *public* key). You use your token to *decrypt* messages that were sent
> to you--and at that time, even if the token is malicious there's nothing
> it can do to mess with the encryption.
> 

I assumed the public key of the recipient is transferred to the token so
that it can do the encrytion internally. This is one of the things I
worry about. If the token does the encryption (and signing) operations,
it needs randomness. Something that is often messed with and hard to
produce reliably compared to a device with user interaction.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: OpenPGP digital signature
URL: </pipermail/attachments/20161216/195ef49d/attachment.sig>