<p>It is a feature that this is not possible. You do not want to use a printer to print paper wallets as this is highly insecure.
Printers have a track record of having low security - so people can hack the printers - wait for it to print something that looks like a private key and send them home(not yours).
Also some printers have build-in hard drives that save every document printed - so there are also attack vectors where the printer does not need to be compromised before printing.
Also have a look here: <a href="https://events.ccc.de/congress/2011/Fahrplan/events/4780.en.html" rel="nofollow noreferrer">https://events.ccc.de/congress/2011/Fahrplan/events/4780.en.html</a>
<a href="https://media.ccc.de/v/28c3-4780-en-print_me_if_you_dare" rel="nofollow noreferrer">https://media.ccc.de/v/28c3-4780-en-print_me_if_you_dare</a> </p>

CC BY-SA 3.0
2018-02-06T00:17:41.163Z
Can you expand on the reason(s) this is insecure?
Elias Naur
CC BY-SA 3.0
2018-02-06T10:46:16.923Z
I edited my answer adding some reasons. Hope this helps understanding the problem.
ligi
CC BY-SA 3.0
2018-02-07T11:20:43.413Z
I'm using the USB-interface on the printer exactly to avoid these security issues. The printer does not have wireless networking and its network port has never been connected. In fact, it has never been connected to anything other than USB-sticks and the Mycelium Entropy. Of course, there is still a risk, but nowhere big enough to rule out this mode of cold storage.
Elias Naur
CC BY-SA 3.0
2018-02-04T23:29:43.443Z
2018-02-06T10:45:32.790Z
2018-02-06T10:45:32.790Z
ligi
<p>Is it possible for a Trezor or Trezor T to connect with and directly interface with a printer? The <a href="https://mycelium.com/mycelium-entropy.html" rel="nofollow noreferrer">Mycelium Entropy</a> device is very useful to print paper wallets while minimizing MITM attacks. I'd like the Trezor to do the same.</p>

CC BY-SA 3.0
2018-01-16T13:30:26.083Z
Unfortunately it's not possible.
MCCCS
CC BY-SA 3.0
2018-02-02T16:34:37.717Z
Is that a fundamental limitation or can it be programmed to do so?
Elias Naur
CC BY-SA 3.0
2018-02-03T14:26:52.910Z
It's actually a good suggestion, you should ask Trezor devs: https://gitter.im/trezor/community
MCCCS
CC BY-SA 3.0
2018-02-04T23:30:29.717Z
Don't do it - printers have really weak security - would never print a private key that should hold any value
ligi
<paper-wallet><trezor>
Connect Trezor (T) directly to a printer to generate paper wallets
Elias Naur
# Connect Trezor (T) directly to a printer to generate paper wallets

(Asked by: username_0 on 2018-01-16)

Is it possible for a Trezor or Trezor T to connect with and directly interface with a printer? The [Mycelium Entropy](https://mycelium.com/mycelium-entropy.html) device is very useful to print paper wallets while minimizing MITM attacks. I'd like the Trezor to do the same.

**Tags:** paper-wallet, trezor

> **Comments:**
> **username_1**: Unfortunately it's not possible.  
> **username_0**: Is that a fundamental limitation or can it be programmed to do so?  
> **username_1**: It's actually a good suggestion, you should ask Trezor devs: https://gitter.im/trezor/community  
> **username_2**: Don't do it - printers have really weak security - would never print a private key that should hold any value  

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## 1 answers

### Answer by username_2 on 2018-02-04. Score: 1

It is a feature that this is not possible. You do not want to use a printer to print paper wallets as this is highly insecure.
Printers have a track record of having low security - so people can hack the printers - wait for it to print something that looks like a private key and send them home(not yours).
Also some printers have build-in hard drives that save every document printed - so there are also attack vectors where the printer does not need to be compromised before printing.
Also have a look here: <https://events.ccc.de/congress/2011/Fahrplan/events/4780.en.html>
<https://media.ccc.de/v/28c3-4780-en-print_me_if_you_dare>

> **Comments:**
> **username_0**: Can you expand on the reason(s) this is insecure?  
> **username_2**: I edited my answer adding some reasons. Hope this helps understanding the problem.  
> **username_0**: I'm using the USB-interface on the printer exactly to avoid these security issues. The printer does not have wireless networking and its network port has never been connected. In fact, it has never been connected to anything other than USB-sticks and the Mycelium Entropy. Of course, there is still a risk, but nowhere big enough to rule out this mode of cold storage.  

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