The manifest:checksum-type attribute supports the algorithms supported by the W3C XML Enc Core specification. MD5 in theory could be used by specifying an URI that identifies MD5. The XML Enc Core specification does not specify an URI for MD5. The reason can be found in section 6.2 of the XML DSig specification ( http://www.w3.org/TR/2002/REC-xmldsig-core-20020212/): "Use of MD5 [MD5] is NOT RECOMMENDED because recent advances in cryptanalysis have cast doubt on its strength. " Under this circumstances, it does not appear to be reasonable that the ODF specification defines an URI for MD5. MD5 anyway could be used by using an implementation defined URI as attribute value.