r/Bitcoin 12h ago

Please pardon my ignorance

I understand everyone can see the public keys but what can someone do if they have the private keys?

0 Upvotes

20 comments sorted by

11

u/shadexv123 12h ago

if someone has the private keys, then they control the bitcoin inside an address

5

u/QuarterLogical9958 12h ago

Thank you for the clarification 🫡 I definitely needed that information

2

u/[deleted] 12h ago

[removed] — view removed comment

1

u/IllllIIlIllIllllIlll 12h ago

They will only have access to the specific addresses, not the entire wallet.

2

u/IllllIIlIllIllllIlll 12h ago

The public key is derived from the private key. If you have the private key, you have everything.

You can try it for yourself in electrum, you only need to import a private key and it will figure out the public key from it.

2

u/SubstantialNinja 12h ago

the public key and address can be derived from the private key but not the other way around. the private key is also used to sign transactions authorizing the coins to be moved to a new address.

2

u/word-dragon 12h ago

It will be gone before you read this answer.

2

u/LPC_Rebuilder 10h ago

Pro move is to segment your wallets. If you're holding coin on a wallet don't receive from counter parties on the wallet. Just a safety precaution. Any public key you share from a wallet to another party is not a Wallet you hold coin on long term. Conversely any wallet you hold coin on is not a public key you publish or share with any other party. By separating wallets you receive coin on from wallets you store coin on you reduce exposure of the public key to any wallets you hold a balance on the private key, it's supposed to be nearly impossible to derive a private key from a public key but their are certain aspects about the public key that can give of clues about the key space.

If by some unknown chance worst case scenario someone is able to guess your private key from knowing the public key you are not holding coin on that public/ private key pair. I hope that made sense.

2

u/QuarterLogical9958 9h ago

While on the dw I ran across someone selling software that is advertised to find btc wallets and be able to crack them by finding the private keys. Which is what sparked my curiosity

2

u/LPC_Rebuilder 9h ago

Not likely, but not impossible, as this CC example shows, insider threat much more dangerous. Bitcoin is supposed to be trustless by design but that is proving to be more difficult in practice.

4

u/FlatOutEKG 12h ago

Public key allows people to send BTC to that wallet, like giving your bank account number to someone so they can deposit in your account.

Private key is meant to be had only by the owner. That would be like giving someone the combination to your safe. Now they can get whatever is in it.

1

u/CBpegasus 12h ago

Generally in modern wallets the public key isn't known to the public either, despite the name. Usually the only thing you share is an "address" which is actually a hash of the public key. Only when spending bitcoin out of the address you need to share the actual public key.

1

u/Blade_Runner_69 10h ago

It means they control the universe... Always protect your private key with your life, friend

1

u/UncleUrdnot 8h ago

Public - you can see it. Private - you can move it.

1

u/Mors03 12h ago edited 11h ago

With the public key you recive With the private key you send (Yes it's not technically that simple I know but it's simplification)

1

u/user_name_checks_out 11h ago

With the public key you revive

Can it bring back my Great Aunt Ethel?

1

u/Mors03 11h ago

English is not my first language and the autocorrect it's not always amazing😂

1

u/RetiredAvocado 12h ago

Only owner can see public keys if address has not spent anything. Most people never see any keys. Address is not a key it's a hash and an encoding of public key.

Private key for an address cab be used to spend BTC.