About: http://webisa.webdatacommons.org/70238897

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	So it may be that the best solution is for your friend to generate a new public-key that he uses for both signing and encrypting.
http://www.w3.org/ns/prov#wasQuotedFrom	serverfault.com