 As a result of this work, cryptographers now recommend the use of provably secure padding schemes such as Optimal Asymmetric Encryption Padding, and RSA Laboratories has released new versions of PKCS #1 that are not vulnerable to these attacks.A side-channel attack using branch prediction analysis (BPA) has been described.Many processors use a branch predictor to determine whether a conditional branch in the instruction flow of a program is likely to be taken or not.