  We show that the intermittent dynamics observed in the inertial interval of
Sabra shell model of turbulence can be rigorously related to the property of
scaling self-similarity. In this connection, the space-time scaling symmetries
(like in the K41 theory) are replaced by the new hidden scaling symmetry, which
is an exact symmetry of inviscid dynamics represented in special rescaled
coordinates and times. We derive the formulas expressing anomalous scaling
exponents in terms of Perron-Frobenius eigenvalues of linear operators based on
the self-similar statistics. Theoretical conclusions are verified by extensive
numerical simulations.
