Hash pointers explained: how blocks link and detect tampering
Thread269 words
Explains hash pointers as pointers containing the previous block's hash, so changing any block changes its hash and breaks the link, making blockchains tamper-evident.
Key claims
Modifying a block's data changes its hash and breaks the link to the next block
0/ What are Hash Pointers? 馃鈥嶁檪锔忊湪
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1/ Hash pointers are a type of pointer that point to a specific location in a data structure, specifically a block in a blockchain. They are an essential part of the structure and security of blockchains.
2/ To understand hash pointers, it's helpful to know what pointers are more generally. Pointers are variables that store the address of another variable, allowing you to indirectly access and manipulate the value of a variable by referring to its memory location.
3/ In blockchains, each block contains a unique code called a hash, which represents the data stored in the block. The hash is created by running the data through a hash function, which generates a fixed-size string of characters representing the data.
4/ if you need a recap on hash functions, check out my thread from earlier today!
4/ The hash pointer in a block points to the previous block in the chain, as the data from which the hash pointer is generated also includes the previous' block header, thereby creating a link between the two blocks.
5/ This link is important because it ensures the integrity of the data in the blockchain. If any data in a block is modified, the hash of the block will change, breaking the link and making it easy to detect the change.
6/ Hash pointers hence allow blockchains to maintain a tamper-evident record of transactions and other data. They are an essential component of the security and integrity of blockchains.
7/ I will introduce more cryptographic primitives over the next few days, so stay tuned! 馃鈥嶁檪锔忊湪