In intrusion detection, how to send alert messages without scaring the attacker in the very early state is a practical issue. The solutions for this problem vary. Sentinel nodes can send encrypted messages instead of plaintext, but for further security, for example, even the communication traffic needs to be balanced to deceive the attacker.

In this paper, the authors propose a new cryptographic primitive called the blind coupon mechanism (BCM) to solve the above problem in a scientific way. The generalized scheme of BCM is based on the subgroup membership and escape problems. Moreover, a specific construction of BCM is given with elliptic curve cryptography. The security of the scheme is formally analyzed.

Although this paper is self-contained enough for scientific readers, engineering readers might miss experimental examples for BCM in the “spreading alerts quietly” scenario. Also, a comparison with other solutions for spreading alerts quietly might be interesting and useful for readers without cryptographic expertise.