Admin: Created page with "'''This is an old idea which is much better implemented by Two-factor mnemonic phrases''' I believe it was Casascius that [htt..."

2019-07-31T12:00:17Z

Created page with "'''This is an old idea which is much better implemented by Two-factor mnemonic phrases''' I believe it was Casascius that [htt..."

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'''This is an old idea which is much better implemented by [[Mnemonic_phrase#Two-Factor_Mnemonic_Phrases|Two-factor mnemonic phrases]]'''

I believe it was Casascius that [https://bitcointalk.org/index.php?topic=56414.0 first talked about the idea] of a "2 factor paper wallet". TL;DR - it's a system to securely generate BTC addresses given the risk of any particular machine being injected with trojans.

(If you can find the original discussion, that would be great)

See also [[User:Casascius/Base58Check-encoded_objects_proposal#Proposed_specification_for_a_multi-part_key_using_EC_multiplication|this BIP]].

== How it works ==

# Trusted 3rd party generates a key pair (''Private_1'', ''Public_1''), and sends them to you in the form of laminated paper. ''Public_1'' is derivable from ''Private_1''. The keys are deleted after sending.
# You generate an addition key pair (''Private_2'', ''Public_2'') on your own machine.
# You cryptographically combine ''Public_1'' and ''Public_2'' and get ''Public_final'' - a Bitcoin address.
# You transfer BTC into ''Public_final''
# At a later time, when you want to withdraw funds from it, you combine ''Private_1'' and ''Private_2'' to get ''Private_final'', and withdraw.

The point of the system is that an attacker would have to break into both your systems in order to withdraw funds. It is a way to securely store Bitcoins even if your system potentially contains trojans, without trusting a 3rd party. This scheme can in fact be done with N parties, with each additional part just adding security to the system (suspect Party1 is a CIA snitch? That's ok, because all it takes for this to be secure is one secure party).

==Source==

[http://bitcoin.it/ http://bitcoin.it/]
[[Category:Paper wallets]]
==See Also on BitcoinWiki==
* [[MAKE]]
* [[Zeepin]]
* [[Meters]]
* [[Consentium]]
* [[Extolabs]]

Two-factor paper wallet - Revision history

Admin: Created page with "'''This is an old idea which is much better implemented by Two-factor mnemonic phrases''' I believe it was Casascius that [htt..."