In iOS 5, signing a certificate with an MD5 signature is not supported.

ENGADGET: Apple seeds iOS 6 beta 4 to developers: here's the changelog

White seemed to agree, saying that he thought Burris could be appointed without his signature on the certificate.

CNN: Burris appointment valid, Illinois high court says

Nancy Erickson, the Senate secretary, initially rejected Burris' appointment Monday because his certificate of appointment was missing the signature of Illinois Secretary of State Jesse White.

CNN: Feinstein says Burris should get Senate seat

Burris, in turn, asked the Illinois court to force White to sign the certificate by ruling that White's signature is, in effect, nothing more than a ceremonial, nondiscretionary government action.

CNN: Burris appointment valid, Illinois high court says

Reid and Durbin said Burris' certificate, since it lacks White's signature, violates a Senate rule that has been in place since the 19th century.

CNN: Democrat: Blagojevich 'called our bluff' on Senate pick

White, however, disputed the claim that his signature was needed on Burris' certificate, saying Wednesday that he was the "fall guy" for politicians who oppose Burris.

CNN: Democrat: Blagojevich 'called our bluff' on Senate pick

Democrats expect Burris to show up on Capitol Hill on Tuesday with a certificate of appointment signed by Blagojevich but missing the signature of Illinois Secretary of State Jesse White, according to the Democratic source and a Democratic Senate leadership aide.

CNN: Burris to meet with Dem leaders, source says

The certificate itself contains the issuer's name (for example, Chase Manhattan), a serial number, a signature algorithm ID, an expiration date, an employee's public key and unique identifiers for both the issuer and the employee.

CNN: Technology - E-Signature Act may drive demand for authentication technology