本文档指定了三种适用于需要轻量级加密实现的应用程序的分组密码: -目前:一种轻量分组密码，其块大小为64位，密钥大小为80或128位； -CLEFIA:一种轻量分组密码，块大小为128位，密钥大小为128、192或256位； -LEA:一种轻量分组密码，块大小为128位，密钥大小为128、192或256位。

This document specifies three block ciphers suitable for applications requiring lightweight cryptographic implementations: — PRESENT: a lightweight block cipher with a block size of 64 bits and a key size of 80 or 128 bits; — CLEFIA: a lightweight block cipher with a block size of 128 bits and a key size of 128, 192 or 256 bits; — LEA: a lightweight block cipher with a block size of 128 bits and a key size of 128, 192 or 256 bits.