rowguid in android doesn't work

I've got a field that is a rowguide field. In vs on a window machine I use this query:

 INSERT INTO SmartTipiDoc (CODICE, DESCRI, rowguid) SELECT 'ddt', 'DDT', lower(hex(randomblob(16))) UNION ALL SELECT 'iva', 'IVA', lower(hex(randomblob(16)));

But on the android emulator I've got this error:

 error: could not prepare statement (1 not authorized to use function: randomblob)

What can I do? Can I use the NEWID() function?

Many thanks