DRECON: DPA Resistant Encryption by Construction. Side-channel attacks are considered as one of the biggest threats against modern crypto-systems. This motivates the design of ciphers which are naturally resistant against side-channel attacks. The present paper proposes a scheme called DRECON to construct a block cipher with innate protection against differential power attacks (DPA). The scheme is motivated by tweakable block ciphers and is shown to be secure against first-order DPA using information theoretic metrics. DRECON is shown to be less expensive than masking and re-keying countermeasures from the implementation perspective and can be efficiently realized in both hardware and software platforms. On FPGAs especially, DRECON can optimally utilize the abundant block RAMs available and therefore have minimal overheads. We estimate the cost overhead of DRECON in micro-controllers and FPGAs, two common targets for cryptographic applications. Finally we demonstrate practical side-channel resistance of a DRECON implementation on a Xilinx Virtex-5 FPGA (SASEBO GII board).