1. A system, comprising: a storage device configured to store a plurality of files; and a host computing device configured to implement an operating system including a file system, wherein said file system is configured to store said files to said storage device and to manage accesses to said storage device, wherein said accesses are generated by applications distinct from said operating system; wherein said file system is further configured to generate and store a respective signature of each of said plurality of files, and to compare a respective signature of a given one of said files against a corresponding validation signature, wherein the file system is further configured to: store the validation signature in a write-once storage location associated with the given one of said files; and prevent the validation signature stored in the write-once storage location from being altered after being stored, until the given one of said files is deleted; and wherein said file system is further configured to compute an updated version of said respective signature of said given file in response to detecting an operation to modify said given file, wherein said operation is generated by one of said applications, and wherein said file system is further configured to compare said updated version of said respective signature against said corresponding validation signature subsequent to computing said updated version of said respective signature.