Today I had an exam in communication security (SSL, IP-Sec, Crypto Hash, etc.). The exams are the main reason I hadn't blogged in a while. But excuses aside.
One of the questions was about how a CA signs some certificate (attribute certificate), and includes the validation key of Alice (so Bob can be sure that Alice really signed the data in the certificate). Anyhow, the lecturer, who wrote the exam, had a mistake. He wrote A.s which means Alice's signature key (private), while he meant to write A.v which means Alice's validation key (public). So, when our lecturer found out about the mistake, he wrote to the board "Q2 s/A.s/A.v/". I don't know how many students appreciated the little joke during the exam (did I mention it was difficult?), but I'm sure it made me smile.