Where does attack collide?

A deliberate attempt to violate a system's security policy, analysed against an explicit model of what the adversary can do. Dolev and Yao fixed the canonical model in 1983: the attacker controls the network entirely, can read, intercept, and forge any message, but cannot break the cryptography, so a protocol is secure if it survives that adversary. Manadhata and Wing's 2011 attack surface metric counted the entry points, exit points, channels, and untrusted data items through which an attack can reach a system. MITRE's ATT&CK knowledge base, described by Strom and colleagues in 2018, catalogues the tactics and techniques real intrusions use, so that a defence can be tested against observed behaviour rather than imagined threats. What distinguishes this meaning is that an attack is defined relative to a stated attacker, and a security proof is a proof about that attacker and no other.[1][2][3]

Unit

An adversary acting against a system or protocol

Recovery means

Incident response, containment, eradication, and restoration of the system to a known-good state

Measured by

Attack surface metric; ATT&CK technique coverage; successful versus attempted intrusions

The positive aim in war, seeking to seize or destroy, as against defence, which seeks to hold. Clausewitz argued in the 1830s that defence is the stronger form of war with the negative object, and attack the weaker form with the positive one, so an attacker must have a margin of strength and will reach a culminating point beyond which the advantage reverses. Jervis's 1978 essay turned the pair into a variable, the offence–defence balance, and showed that when attack is easy and hard to distinguish from defence, the security dilemma is most severe. Biddle's 2004 study found that force employment (the modern system of cover, concealment, dispersion, and combined arms) matters more to the outcome of an attack than numbers or technology. What distinguishes this meaning is that attack is one of two forms of a single activity, and its meaning is fixed by its relation to the other.[4][5][6]

Unit

A force acting against an opposing force, over a campaign or battle

Recovery means

Not applicable, the criterion is whether the attacker reached its object before the culminating point

Measured by

Territory taken; loss-exchange ratios; the offence–defence balance as inferred from technology and doctrine

A sudden, coordinated sale of a currency that exhausts the central bank's reserves and forces it to abandon a pegged exchange rate. Krugman's 1979 model showed that under a peg financed by money creation, the attack is not a panic but an equilibrium: rational speculators buy the reserves at the exact moment the shadow floating rate reaches the peg, and the collapse is timed to the fundamentals. Obstfeld's 1996 second-generation models made the attack self-fulfilling: a government that would defend the peg absent an attack may rationally abandon it once the attack raises the cost of defence, so multiple equilibria exist and the attack can occur without a deterioration in fundamentals. What distinguishes this meaning is that the attackers are many, uncoordinated, and acting in their own interest, and the attack succeeds by arithmetic rather than force.[7][8]

Unit

A pegged currency and the speculators who hold it, over the run to abandonment

Recovery means

Re-pegging or a managed float once reserves and credibility are rebuilt

Measured by

Reserve losses; exchange-market pressure indices; timing of the peg's collapse relative to the shadow rate

Two intentional torts that the lay word attack runs together. The Restatement (Second) of Torts fixed the elements in 1965. Battery under §13 is an act intended to cause a harmful or offensive contact with another person, or an imminent apprehension of such contact, where a harmful contact results. Assault under §21 is the same intent where the other person is put in imminent apprehension of contact, whether or not contact follows. Neither requires injury, malice, or a weapon; an unwanted touch is a battery and a raised fist is an assault. What distinguishes this meaning is that an attack is decomposed into an intent and an effect on a specific person, and liability attaches to each combination separately.[10][9]

Unit

One act by a defendant against one plaintiff

Recovery means

Damages, including nominal damages where no harm resulted

Measured by

Findings on intent, contact, and apprehension; damages awarded