17 March 2011
Yes. Its permitted First understand the purpose of a TDS or TCS certicate. It is only to give the proper credit to the assessee of the amount that has been deducted and paid on his behalf. Another important aspect to be noted is that now there is no requirement of giving the copy of the certificate. All that is needed are the payment details. Even if you have a TDS certificate but the amount of Tax has not been paid by the deductor no credit will be given to you. Digital Signature is used for the purpose of only authenticating the document. Ultimately TDS credit will be only given as per 26AS.
17 March 2011
http://law.incometaxindia.gov.in/DIT/File_opener.aspx?page=CIR&schT=&csId=f0989c2f-5e1a-4950-a55f-85cc8f37984e&crn=2/2007&yr=2007&sch=&title=Taxmann%20-%20Direct%20Tax%20Laws
See the above circular. Though it specifically mentions form 16 but digital signature on form 16A is also applicable.