Electronic voting systems are increasingly used in electoral processes ranging from specialized stand alone machines, up to complete paperless and remote voting system. Votes secrecy and confidence are necessary in any electoral process. Public or private key cryptographic systems can be used in LAN or WAN facilities. Low level cryptographic structures and basic algorithms are mentioned. Enhancement of security levels in distributed voting schemes, are shown based in concatenated operations before transmission. Finally, processing time reduction with specialized hardware and mixed cryptosystems are discussed