字母组 meaning in English

group of letter

In statistical attacks on ciphers the known frequency of various bigrams , in a given language , can be used in attempts to break the cipher
在对密码的统计攻击中，可用已知语言的各双字母组的频度来攻破密码。
Information processing . conversion between the two coded character sets of iso 646 and iso 6937 - 2 and the ccitt international telegraph alphabet no 2
信息处理.位编码字符组和号国际电报字母组之间的转换