Abstract: There are narrowband and broadband subliminal channels in the Elliptic Curve Digital Signature Algorithm (ECDSA)，but broadband subliminal channel cannot be safely used. Therefore, the real-time test of narrowband subliminal channel was done. The reasonable bit rate of the sent message was confirmed when the capacity and real-time requests of narrowband subliminal channel were satisfied. The result shows narrowband subliminal channel can be effectively used in ECDSA.

Key words: Elliptic Curve Cryptosystem (ECC), digital signature, information hiding, narrowband subliminal channel, Miracl large number library

摘要： 针对阈下信道技术在椭圆曲线数字签名中的应用可能以及存在的安全隐患问题，通过对其中存在的窄带阈下信道进行实时性测试，在平衡传输信息容量与签名时间的条件下，确定了合理的阈下信息传输位数。实验结果表明，窄带阈下信道在椭圆曲线数字签名中可以被有效利用。

关键词: 椭圆曲线密码体制, 数字签名, 信息隐藏, 窄带阈下信道, Miracl大数库