The transaction block chain is a ledger that contains all the transactions and prior activities that have taken place since the creation of an account and validates any ownership of currency units that have been given at any time. It is a way of calculating if digital wallets have an accurate spendable balance. The blockchain also ensures new transactions use current coins that are owned by the spender. It is a shared ledger which all Bitcoin users rely on, and its chronological order and integrity of the block chain are enforced by cryptography.
The block chain prevents double spending or cryptocurrency code manipulation that allows the same currency to be duplicated and sent to multiple recipients.
Private keys also known as a seed, are secret pieces of data that are used for signing transactions which every cryptocurrency holder has to authenticate their identity with. Users make up their private keys ranging from 1 to 78 digits or random number generation to create a private key. This is the only way a user can obtain and spend cryptocurrency; without the private key, a user’s account is rendered useless until the key is obtained.
The signature provided prevents the transaction carried out from being altered by anyone once issued. It is a means of ensuring people are careful with their private keys and always remember them, as losing your key will be equivalent to throwing cash away. It’s possible to have another private and start accumulating cryptocurrency, but it won’t be the same as the holding you had in your previous lost private key.