Which encryption algorithm is BEST suited for communication with handheld wireless devices?

As it provides much of the same functionality that RSA provides: digital signatures, secure key distribution,and encryption. One differing factor is ECC’s efficiency. ECC is more efficient that RSA and any other asymmetric algorithm.

The following answers are incorrect because :

RSA is incorrect as it is less efficient than ECC to be used in handheld devices.

SHA is also incorrect as it is a hashing algorithm.

RC4 is also incorrect as it is a symmetric algorithm.

Reference : Shon Harris AIO v3 , Chapter-8 : Cryptography , Page : 631 , 638.