Mauro Real SÃO BERNARDO DO CAMPO, Brazil 14 Questions 5 Answers 0 Best Answers 94 Points View Profile Mauro RealIn: BlockchainLearner Asked: February 5, 20192019-02-05T20:32:19+00:00 2019-02-05T20:32:19+00:00 Is it possible to modify the data once it is written in a block? Why? Answer and explain your answer blockchain block immutable Share Facebook 1 Answer Voted Oldest Recent Mounir Missaoui Ariana, Tunisia 0 Questions 1 Answer 0 Best Answers 10 Points View Profile Mounir Missaoui Learner 2019-02-10T06:37:53+00:00Added an answer on February 10, 2019 at 6:37 am Hi Mauro , Great question my friend. However the answer is “it’s not a yes or no issue”: short answer, yes but it’s not something good to do. Long answer, Blockchain is a democratic network based on resources meaning the if your computational power (CPU or GPU) is greater than the rest of the network combined ,then the Blockchain considers you as the majority (check : 51% attack in Blockchain ) at that moment you can change what ever block you wish to change then re-mine your way back the correct block and timestamp and that’s what we call the Double spend attack 0 Reply Share Share Share on Facebook Share on Twitter Share on WhatsApp Leave an answerCancel replyYou must login to add an answer. Username or email* Password* Captcha* Click on image to update the captcha. Remember Me! Forgot Password?