About: http://webisa.webdatacommons.org/299884683

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Please make a complete example: there is nothing obviously wrong with what you are showing us, so my best guess is that the problem lies in what you are not showing us (i.e. where do key, keylen and cipher come from?)
http://www.w3.org/ns/prov#wasQuotedFrom	stackoverflow.com