Can someone please direct this code/internet architecture-challenged Forum member to an article, blogpost, book, anything that explains the Blockchain concept in the most basic, easy to understand way?
The way I understand it is block chains, at least for bitcoin usage, are a distributed (transparent) ledger. Each value within the ledger is processed through a one-way cryptographic hashing algorithm that produces a representation of the data called a message digest. Hashing algorithms are typically used in secure communication as a quick means of condensing arbitrary-sized data into a fixed-length string of characters, letters, etc. For bit coin purposes, each hash in sequence is the result of computing the previous hash value using the same cryptographic function. A secure hashing algorithm should change every bit of the resulting hash value for even the smallest change in the value being input. The reason for this, is that hashing functions are typically used in secure communication to condense arbitary-sized data (ideal for data storage) and to ensure integrity of a message. When you compose a e-mail, the message digest associated with that e-mail can be generated by the sender and receiver. If an attacker modifies the original message, the receiver would get a different message digest when they processed the plain-text message. The sender will encrypt the message digest so that only the corresponding encryption key can be used to decrypt it. If the attacker modifies the message digest, they would have to encrypt it with their own encryption key and the receiver would be unable to decrypt it. In both cases, the receiver can be reasonably certain the plain-text message and the message digest came from the sender with whom they are communicating. In bit coin, the ledger takes advantage of these characteristics since anyone with the ledger can recalculate the resulting message digest. If the message digest displayed by the ledger does not match, then someone has tampered with the ledger. The message digest might be different because someone attempted to remove a transaction from the ledger, thus breaking the chain. This ensures accountability of the ledger. I'm sure those that work with bit coin probably have a much better grasp on this than I do, but this is how block chains were explained to me. I've read a couple articles looking to apply the block chain approach to security in other areas, as to make tampering more transparent. It's worth noting that insecure hashing algorithms might be good for performing basic checksums, but they are vulnerable to crypt-analysis attacks that seek to produce the same message digest using different inputs. How this might be used in the bit coin scheme is beyond my understanding outside of its role in making fraudulent ledger entries. Source: http://www.csoonline.com/article/3050557/security/is-the-blockchain-good-for-security.html
Thank You Techwiz for taking the time to write all that to try to help me broaden my understanding. A lineup of falling dominoes I undertand -- blockchains not so much. I'll have to chew on that for a while, although I prefer carrots
