A method and system for verifying content of a resource. A first computer creates, in a markup language document, a markup element including a first characteristic of the content of the resource stored at a second computer coupled to the first computer. The first characteristic is extracted from the markup element in the markup language document. The resource is retrieved from the second computer according to a resource indicator that references the resource. A second characteristic of the content of the retrieved resource is generated by computing a hash of the content of the retrieved resource according to a particular hash algorithm. The second characteristic is ascertained to be identical to the first characteristic. The resource indicator and the first characteristic are included in the markup element. The created markup element includes a first attribute-value pair and a second attribute-value pair within distinct non-overlapping portions of the markup element.