To secure something in response to an opposing threat or security measure; to take protective action against another's security.
From counter- + secure (from Latin securus, meaning safe or free from care). A military or defensive term for responsive security measures.
During the Cold War, as one superpower secured its borders and weapons, the other would countersecure—creating the arms race escalation cycle. Cybersecurity now uses this terminology when describing how attacks and defenses constantly evolve against each other.
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