Quote from: Nissi on April 22, 2013, 12:18:36 AM

Does anyone have a good (Concise) explanation of the BTC and/or LTC hashing algorithms and how confirmations work... I would like to explain this to a sceptic but cant find succinct resources...

I'd suggest you not waste your time on a skeptic. If they aren't curious or interested, then they aren't going to accept anything you say about it.

On the other hand if they are curious or interested, then I'd send them here to bitcointalk.org where any questions or concerns they may have can be addressed.

As far as I know there isn't a "concise" explanation of the SHA-256 hashing process. It is a rather complex algorithm. About the best I've seen is the wikipedia page:

http://en.wikipedia.org/wiki/Sha-256

As for how confirmations work, your best bet is to make sure that you understand the process well enough to explain it yourself. That way when the skeptic responds with questions, you'll be ready to answer, and you'll be able to adjust your presentation to their particular level of understanding. Is there something in this thread that isn't clear? This post from earlier in this discussion thread is about as concise as I can get it:

Quote from: DannyHamilton on April 21, 2013, 03:41:34 PM

- snip -

The computer selects a set of unconfirmed transactions.

A block header for that set of transactions is created

A double SHA-256 hash of the block header is calculated.

If the hash value is less than the target difficulty required by the protocol, the header and set of transactions are considered a valid block.

If the hash value is not less than the target difficulty, a number in the header called a "nonce" is incremented.

A double SHA-256 hash of the block header is calculated.

If the hash value is less than the target difficulty required by the protocol, the header and set of transactions are considered a valid block.

The nonce increment, double hash, and compare steps are repeated as fast as possible until either:

A hash value less than the target difficulty is found
A valid block is received from a peer

In either case the valid block (received or created) is added to the local copy of the blockchain and broadcast to all connected peers.

The process then begins all over again with a new set of unconfirmed transactions.

The block that contains a transaction is the first confirmation for that transaction. After that every new block added to the blockchain is another confirmation.