Public and private keys, explained with a mailbox (not just "it's like a passwor

[odolvlobo]

Your explanation is simple and straightforward and is good enough for most people. However, it is not completely accurate.

The reality is that:
1. the contents can only be retrieved from the back of the mailbox (which is conveniently labeled with the private key), and
2. all mailboxes are completely open in the back and anyone can chose any mailbox, reach into the back, and remove its contents.

The security of this system comes from three facts:

1. There is no way to associate the back of a mailbox with its front (and vice versa). sorry -- brain fart.
2. It takes time and effort to reach into a mailbox.
3. Practically all of the mailboxes are empty. It would take centuries of reaching into mailboxes to find a single one that contains something.

[tbct_mt2]

Your explanation is simple and straightforward and is good enough for most people. However, it is not completely accurate.

The security of this system comes from three facts:

1. There is no way to associate the back of a mailbox with its front (and vice versa).
2. It takes time and effort to reach into a mailbox.
3. Practically all of the mailboxes are empty. It would take centuries of reaching into mailboxes to find a single one that contains something.

Private keys used to create public keys.
Public keys used to generate Bitcoin addresses.

Two processes are one-way, the first one from Elliptic curve multiplication (ECC) on the secp256k1 curve, the second one from hashing SHA256, both are one way. If these processes are not one-way, and from a Bitcoin address, it's possible to find Bitcoin private keys easily, then spend coins of the others, Bitcoin blockchain is useless, and bitcoin has no value.

https://bitcoinsecurity.org/learn/private-key/
https://bitcoinsecurity.org/learn/public-key/
https://bitcoinsecurity.org/learn/address/

[knowngunman]

There are countless users who have completely wrong ideas that if you lose the private key that implies you just won't be able to use your address anymore. They think there will always be a way to recover the key, just like you recover a password... That's false, and it will never be possible.

I am sorry but I am feeling lost when reading this post because it is confusing and kind of misleading me to a thought like if I lost my Bitcoin private key, I still can access my bitcoin, and it means like I am still safe.

Thought I was the one who felt lost reading that part. I read it multiple times but couldn't grab the exact message because it's contradicting. Losing your private keys won't make your address invalid. The address can still receive coins and add up to your balance but there is no point sending coins to address you can not longer access the private keys unless you want to lose the coin forever.

You can always use your address to receive funds, but you cannot spend the funds sent to that address without the private key that unlocks the funds sent to the address

This is true but only a mad person would use that address to receive funds. If you don't have the private keys to access your wallet, it's wrong to say you're using it to receive funds, you're using it to burn funds instead. 

[EluguHcman]

That total incapacity for recovery only exists if there is personal custody. If you lose your password to an account at an exchange house like Binance or Coinbase, it's a completely different scenario, because those exchange houses have your private key for you, that's what custody means. So, you can recover your account using traditional account recovery methods.

So, in short, you are insinuating that people should use custodial means to hold their coins? Also this is entirely different from the title of your topic which is about private key and public key explained, and not about in difference to exchanges.

Exchanges have their own downsides which can not make me use exchanges to hold coins.

Some Bitcoin users had also lost their interests of self custody with their funds which is one of the reasons Satoshi had to invent Bitcoin just to create an atmospheric conditions that individual users would have the privilege to control their funds through which, users are in charge of their seed phrase without haven to trust it in a third parties custody.

Instead, how to spend the money easily is what they finds more interesting as the exchange is Centralized. Until such users falls victim, they won't know the risks in giving your exchange the right to hold your recovery keys.
Of course that is pure loosing of self right because the exchange will also have to decide your means in the space.

Exchange is never advice able to be used in holding your coin for long because it can be risk to lost right and accessibility of your privacy and funds.