Microsoft Office password protection the password can be determined through guesswork or social engineering, the underlying cipher is not important. Microsoft Office password protection Microsoft Office password protection is a security feature to protect Microsoft Office (Word, Excel, PowerPoint) documents with a user-provided password. As of Office 2007, this uses strong encryption; earlier versions used weaker systems and are not considered secure. Office 2007–2013 employed 128-bit key AES password protection which remains secure. Office 2016 employed 256-bit key AES password protection which also remains secure. The Office 97–2003 password protection used 40-bit key RC4 which contains multiple vulnerabilities rendering it insecure. Microsoft Office applications
Most recent common ancestor Most recent common ancestor In biology and genealogy, the most recent common ancestor (MRCA, also last common ancestor (LCA), or concestor) of any set of organisms is the most recent individual from which all the organisms are directly descended. The term is also used in reference to the ancestry of groups of genes (haplotypes) rather than organisms. The MRCA of a set of individuals can sometimes be determined by referring to an established pedigree. However, in general, it is impossible to identify the exact MRCA of a large set of individuals, but an estimate of the time at which the