Hashes & Merkle Trees in Blockchain Mechanics

Hash Functions take input of any length and produce a fixed-length string which means that one can use hashes on something as small as a few characters or as large as an entire document or even files of huge sizes in GBs and above. 

On the other hand enabled by these hash functions, Merkle tree represent hash-based data structure that is a generalization of the hash list and represent structure in which each leaf node is a hash of a block of data, and each non-leaf node is a hash of its children. Both Hash functions and Merkle Trees are cardinal to the mechanics of any Blockchain. 

This video focuses on a simple explanation of understanding Hashes and Merkle Trees. Hash functions SHA-256 and RIPEMD-160 have been discussed in little detail being peculiar to Bitcoin blockchain.

Your passwords can be cracked easily if less then 16 Characters now!!!!

1.    When the IT security big bang of Do's and Don'ts started some years back it was widely advertised to the Cyber masses to keep their respective passwords any thing more then 8 characters with a mix and match of capitals and smalls with special characters...then this was increased to 10 and last heard it was 15...and was told that 15 character password which is not dictionary based will take years and is actually uncrackable...

2.  As recent as 4 days back,a team of 3(your read it rite it's three) hackers has been able to crack more than 14,800 supposedly random passwords from a list of 16,449 by simply brute forcing!!!!

Image courtesy : http://www.buzzquake.com/tag/brute-force-attacks/

3.   In December it was unveiled by Jeremi Gosney, the founder and CEO of Stricture Consulting Group, that a 25-computer cluster can cracks passwords by making 350 billion guesses per second. It can try every possible word in less than six hours to get plain text passwords from lists of hashed passwords...the word of significance is that you do not need high end machines and east-west architecture to build this kind of IT infra...it is simply a cluster of machines processing power...

4.   The general user in the cyber space like you and me have actually no control over which hashing process websites use and therefore remain at the mercy of an algorithm all would invariably be clueless about...so if you are concerned about security and your email id and password which is the key for so many transactions in your routine life.long passwords are the best defense....and not simply long it has to be a mix match of numerics,capitals,smalls and special characters!!!.

5.  All the best to all of us...keep surfing but avoid drowning!!!! :-)Thanks http://thehackernews.com

Crack 14 Character passwords in Seconds : Objectif Sécurité

1.    There have been articles and forums on the powerful high speed GPU (video card) processors being able to easily provision cracking passwords very apace.A new technology steps here to rule the roast and allow password cracking upto 14 characters in seconds.....this is  called Objectif Sécurité ,by a Swiss security company,which uses rainbow tables on SSD drives.Seemingly it is the hard drive access time and not the processor speed that slows down cracking speed. So using SSD drives can make cracking faster, but just how fast? This technique has a phenominal capacity that could crack passwords at a rate of 300 billion passwords a second, and could decode complex password in under 5.3 seconds.

2.    A real time demo of cracking is available on line at Objectif’s free online XP hash cracker.Just visit the link and see urself by mentioning the hash in the text box.....astoundingly simple....

3. Thanks http://www.objectif-securite.ch/en/products.php