Consonant-Vowel-Consonants for Error-Free Code Entry

Abstract

Recent work on passwords has focused on choosing secure codes, while design for ability to type them error-free has not received as much attention. The difficulties people were having transcribing codes in a security demonstration motivated this study of code transcription difficulty. A pilot study with 33 subjects and a follow-up study with 267 subjects from 24 countries measured performance and preference for codes of varying lengths, patterns, and character sets. The study found long codes with alternating consonant and vowel patterns are preferred and can be more accurately transcribed than shorter numeric or alphabetic codes. Mixed-case and alphanumeric character sets both increased transcription errors. Our proposed CVC 6 code design composed of six Consonant-Vowel-Consonant trigrams is more secure, faster to enter, highly preferred by users, and more impervious to user error when compared to standard codes currently used for security purposes. An extension integrates error detection and correction, essentially eliminating typo problems.