You can choose different encipher algorithms according to requirement . aes is a symmetric block cipher that can process data blocks of 128 bits , using cipher keys with lengths of 128 , 192and 256 bits . because the length of block and key has been expanded , security has been enhanced Aes ( advancedencryptionstandard )是fip ( federalinformationprocessingstandardspublication )在2001年6月發(fā)布的草案,它是分組加密算法,消息分組為128bit ,有三種密鑰長(zhǎng)度128bit 、 192bit 、 256bit ,由于分組長(zhǎng)度和密鑰長(zhǎng)度加長(zhǎng)使得安全性大大的提高,它有望成為21世紀(jì)的加密標(biāo)準(zhǔn)。