Abstract
We discover that a certain deformation of the 1 + 1 dimensional Poincar e superalgebra is exactly realised in the massless sector of the AdS3/CFT2 integrable scattering problem. Deformed Poincar e superalgebras were previously noticed to appear in the AdS5/CFT4 correspondence - which displays only massive excitations -, but they were there only a partial symmetry. We obtain a representation of the boost operator and its coproduct, and show that the comultiplication exactly satisfies the homomorphism property. We present a classical limit, and finally speculate on an analogy with the physics of phonons.