The Secure Spreadsheet is the first and only computer program for cryptographic secure computation aimed at a general public: now two parties, empowered by the latest advancements in cryptography research, will be able to keep their data private and secure while at the same time doing secret calculations on each other\'s inputs. The once killer app of the personal computer, enhanced by the Holy Grail of Cryptography, renews as the soul of the business PC.Every dataset considered private, valuable or confidential will be processed using secure computation techniques in the coming years: The Secure Spreadsheet is the easiest way to start enjoying its benefits due to its retro-compatibility with current IT investments and training. The first version is an Excel Add-in with a minimal learning curve: to securely compute, just colour some cells and press a button. Moreover, multiple secure computations can be carried out concurrently in order to make the most of your currently installed hardware base.Other security solutions for spreadsheets focus on stronger file encryption, granular access control on cells and/or software obfuscators with no mathematical proofs. The Secure Spreadsheet is the first end-user program to offer provably-secure state-of-the-art cryptographically secure computation: secure property rights over data are effectively established by the use of mathematically proven cryptographic techniques, overcoming distrusts between parties.Whenever developing custom secure computation programs, the development team will get to know too many details about the program. In most instances, this security risk is serious enough to question and even prevent the initiation of the software development. However, spreadsheets are minimal computer programs, created without the assistance of third parties: with The Secure Spreadsheet, you don\'t need to involve anyone else to carry out your encrypted secure computations.