1. A computer-implemented method of validating a first negotiable document drawn on an account, comprising: extracting a set of characteristics from a plurality of negotiable documents that are known to be valid for the account; storing a representation of a first subset of the set of characteristics from the plurality of negotiable documents in a public document validation profile associated with the account, wherein the public document validation profile is shared by the financial institution holding the account and at least one other financial institution; generating an image of the first negotiable document using an imaging device; extracting a plurality of characteristics from the image; comparing, using a check validation computer system, the characteristics extracted from the image with at least the representation of the first subset of the set of characteristics to produce a comparison result; if said comparison result is negative, comparing the plurality of characteristics extracted from the image with a private document validation profile associated with the account; and affirming or negating the first negotiable document's validity based on the comparison result.