Bitcoin wallet key length

Suppose you’ve reached the point where you finally see bitcoin as a currency with monetary value,you’re undoubtedly skeptical still,and puzzled by the fact that funds can be transferred and stored in something called a paper wallet?

Understanding what a public and private key is will demystify this confusion.

The Private Key

Bitcoin is a network that simply says who has bitcoin how,and how much of it. (The pronoun ‘who’ is a bit of a misnomer,because coins are tied only to private keys,not to individual people). This description is simple enough,but fundamentally true. The unique number that the network uses to keep track of who has what is the private key. The private key is usually a pretty long number (often time 52 digits of numbers and letters in varying case):

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Let’s say associated with this private key is 1 bitcoin. Whoever has this particular key,whether it be by force,physical possession,memorization,has access to the 1 bitcoin,and is free to do as they please with it. Because access to a particular private key gives this person the ability to use this 1 bitcoin,sharing this private key with everyone else is not a good idea.

The Public Key

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Think of the public key as the one way access to your private key. Otherwise known as an address,this string of numbers and letters is shorter than the private key,and is usually 27 – 34 digits in length. The reason why the public key is a one way access to your private key is that money can only go into,but not out. Borrowing from another technological advent,a public key is an email address. Whoever is in possession of it can only send emails to it,but cannot sent emails out unless the account itself has been compromised (the comparison here is not completely accurate,as knowledge of a bitcoin address has no bearing to compromising a private key,whereas email addresses are typically one half of the credentials in an email account). Retail stores,and other merchants that accept bitcoin will only ever display their public key address when taking payment.

Public keys or addresses are interesting because they’re derived from the private key. In fact many public keys can come from a single private key. So suppose on a bitcoin wallet on your computer,you create 40 new addresses tied to your private key. Sending any money to any of these addresses will let funds accumulate in your private key – the identifier that helps Bitcoin,the network,keep track of who has how much.

The Paper Wallet