Bitcoin Forum
August 23, 2017, 08:40:55 AM *
News: Latest stable version of Bitcoin Core: 0.14.2  [Torrent].
 
   Home   Help Search Donate Login Register  
Pages: [1]
  Print  
Author Topic: Encrypted NFC tag for paper wallet?  (Read 475 times)
kingcolex
Legendary
*
Offline Offline

Activity: 1204



View Profile
June 16, 2017, 08:25:41 PM
 #1

I have found out that you can encrypt messages on NFC tags, this has led me to the idea of using them as parts of an even more secure paper wallet. I have checked the lifespan and they seem to have 10,000 read/write lifespans. I have quite a few of these from a project ~100 or so. I am going to start some test on these, am I missing any reason to why this would be a bad idea?

Benefits over paper wallet: No need to print key (could be held in printer cache)
Need a password to access the key (rather than just peel it)
Easy to stick on to cheap novelty physical coins
Easy to remove and reapply new one after sweeping
Can be placed in NFC blocker sleeve in storage area


Advertised sites are not endorsed by the Bitcoin Forum. They may be unsafe, untrustworthy, or illegal in your jurisdiction. Advertise here.
1503477656
Hero Member
*
Offline Offline

Posts: 1503477656

View Profile Personal Message (Offline)

Ignore
1503477656
Reply with quote  #2

1503477656
Report to moderator
Quickseller
Legendary
*
Offline Offline

Activity: 1148

#PathOfTotality


View Profile WWW
June 18, 2017, 04:56:23 AM
 #2

With a paper wallet with a piece of black paper taped over the private key, you will need to physically touch the paper wallet in order to access the private key. With a NFC tag, you will only need to be in close proximity to the NFC tag, so putting it in a safe may not protect your money depending on available technology.

kolloh
Legendary
*
Offline Offline

Activity: 1064



View Profile
June 19, 2017, 04:30:29 AM
 #3

With a paper wallet with a piece of black paper taped over the private key, you will need to physically touch the paper wallet in order to access the private key. With a NFC tag, you will only need to be in close proximity to the NFC tag, so putting it in a safe may not protect your money depending on available technology.

Sounds like he planned to encrypt the key with a password as well which would help prevent unauthorized access in that manner. Although, you would have to remember the password or you would lose access to the funds. You also have to worry about the security of the device you are using to write to the NFC tags. If you are using an offline machine, this shouldn't be an issue. The added benefit of using NFC tags is that you wouldn't need to worry about your printer caching a copy of the printed paper wallet which some do.

███
██ ██ ██
▄ ▄▄ ▄▄ ▄
▀ ▀▀ ▀▀ ▀
██ ██ ██
▄ ▄▄ ▄▄ ▄
▀ ▀▀ ▀▀ ▀
██ ██ ██
▄ ▄▄ ▄▄ ▄
▀ ▀▀ ▀▀ ▀
██ ██ ██
▄ ▄▄ ▄▄ ▄
▀ ▀▀ ▀▀ ▀
██ ██ ██
!!
██ ██ ██
▄ ▄▄ ▄▄ ▄
▀ ▀▀ ▀▀ ▀
██ ██ ██
▄ ▄▄ ▄▄ ▄
▀ ▀▀ ▀▀ ▀
██ ██ ██
▄ ▄▄ ▄▄ ▄
▀ ▀▀ ▀▀ ▀
██ ██ ██
▄ ▄▄ ▄▄ ▄
▀ ▀▀ ▀▀ ▀
██ ██ ██
██ ██ ██
▄ ▄▄ ▄▄ ▄
▀ ▀▀ ▀▀ ▀
██ ██ ██
▄ ▄▄ ▄▄ ▄
▀ ▀▀ ▀▀ ▀
██ ██ ██
▄ ▄▄ ▄▄ ▄
▀ ▀▀ ▀▀ ▀
██ ██ ██
▄ ▄▄ ▄▄ ▄
▀ ▀▀ ▀▀ ▀
██ ██ ██
██ ██ ██
▄ ▄▄ ▄▄ ▄
▀ ▀▀ ▀▀ ▀
██ ██ ██
▄ ▄▄ ▄▄ ▄
▀ ▀▀ ▀▀ ▀
██ ██ ██
▄ ▄▄ ▄▄ ▄
▀ ▀▀ ▀▀ ▀
██ ██ ██
▄ ▄▄ ▄▄ ▄
▀ ▀▀ ▀▀ ▀
██ ██ ██
███
'
Quickseller
Legendary
*
Offline Offline

Activity: 1148

#PathOfTotality


View Profile WWW
June 19, 2017, 05:04:36 AM
 #4

With a paper wallet with a piece of black paper taped over the private key, you will need to physically touch the paper wallet in order to access the private key. With a NFC tag, you will only need to be in close proximity to the NFC tag, so putting it in a safe may not protect your money depending on available technology.

Sounds like he planned to encrypt the key with a password as well which would help prevent unauthorized access in that manner. Although, you would have to remember the password or you would lose access to the funds. You also have to worry about the security of the device you are using to write to the NFC tags. If you are using an offline machine, this shouldn't be an issue. The added benefit of using NFC tags is that you wouldn't need to worry about your printer caching a copy of the printed paper wallet which some do.
If you encrypt the private key with a password, then anyone who gets close enough will have access to the encrypted private key. Anyone with the encrypted private key could go to a second location with powerful equipment, and attempt to figure out the password -- being that humans are bad at generating 'random' passwords, it would not be unreasonable to say that the password would eventually be figured out.

HCP
Sr. Member
****
Offline Offline

Activity: 336

<insert witty quote here>


View Profile
June 19, 2017, 09:12:55 AM
 #5

If you encrypt the private key with a password, then anyone who gets close enough will have access to the encrypted private key. Anyone with the encrypted private key could go to a second location with powerful equipment, and attempt to figure out the password -- being that humans are bad at generating 'random' passwords, it would not be unreasonable to say that the password would eventually be figured out.
Could you not just store a BIP38 encrypted private key on your NFC then, much like you would on a paper wallet? And for an added bonus paranoia put a password on top of that on the NFC chip data?

Also, the OP did actually mention storing the tag in a "blocker sleeve", by which I assume they meant one of those RFID signal blocking sleeves designed to prevent the tag from being read without physical access to remove it from said sleeve.

kingcolex
Legendary
*
Offline Offline

Activity: 1204



View Profile
June 19, 2017, 02:38:04 PM
 #6

If you encrypt the private key with a password, then anyone who gets close enough will have access to the encrypted private key. Anyone with the encrypted private key could go to a second location with powerful equipment, and attempt to figure out the password -- being that humans are bad at generating 'random' passwords, it would not be unreasonable to say that the password would eventually be figured out.
Could you not just store a BIP38 encrypted private key on your NFC then, much like you would on a paper wallet? And for an added bonus paranoia put a password on top of that on the NFC chip data?

Also, the OP did actually mention storing the tag in a "blocker sleeve", by which I assume they meant one of those RFID signal blocking sleeves designed to prevent the tag from being read without physical access to remove it from said sleeve.
indeed it would be in signal blocking sleeve, so they would have to physically remove it, so that keeps it on the same level as a paper wallet but the password would be an extra level of security, even if only a small one.


The device to do this would be a prepaid Android phone that has never connected and only had NFC tools side loaded from a trusted micro SD.

Pages: [1]
  Print  
 
Jump to:  

Sponsored by , a Bitcoin-accepting VPN.
Powered by MySQL Powered by PHP Powered by SMF 1.1.19 | SMF © 2006-2009, Simple Machines Valid XHTML 1.0! Valid CSS!