As you know, we at CEX.IO always work hard to improve security of our platform even more. Today, we are thrilled to announce that we are going to change current Bitcoin addresses to multi-signature Bitcoin addresses, offering an extra security layer for you.
Considering this upcoming update, please pay attention that your Bitcoin address on CEX.IO will be changed to a multi-sig address on October, 3rd. Considering this, please make sure to check out your new address, beginning with a “3”, in profile and use it to deposit funds to your account, starting from Monday.
Thank you for choosing CEX.IO!
It is a great thing that more exchanges are trying to make their services safer.
I am curious whether CEX.IO is implementing multisignatures all by themselves or they use 3rd party signer like BitGo. As it turned out BitFinex got hacked and they were using multisignatures with BitGo as a partner. Something went wrong there, so just implementing multisignatures is not enough and could just dull your vigilance.
What is a MULTISIGNATURE Cryptocurrency address?
A multi-signature address is an address that is associated with more than one private key. The simplest type is an m-of-n address - it is associated with n private keys, and sending bitcoins from this address requires signatures from at least m keys. A multi-signature transaction is one that sends funds from a multi-signature address.
https://bitcoin.stackexchange.com/a/3729/4334
So you can have 2 of 2 mutisignature address. It means you have 2 private keys for this address. To make a transaction you have to sign a transaction with those 2 keys. You can have one key, your wife second one and transaction is processed only if 2 of you agree to it.
In Bitcoin multisignature addresses begin with 3, but addresses beginning with 3 don't have to be multisignature addresses. It is just an indication that it is a Pay-to-script(P2SH) address. Multisignatures are just a form of Pay-to-script scripts.
Want to know more about about Multisignatues and P2SH?
You can start here:
https://en.bitcoin.it/wiki/Multisignature
https://en.bitcoin.it/wiki/Pay_to_script_hash