From Eric Kvaalen, Les Essarts-le-Roi, France
Simon Goodman worries that quantum computers will leave our online bank accounts open to invasion. Actually, other types of cryptography have been developed to get around this vulnerability. Banks and e-commerce will start to use them instead of existing methods if and when necessary. The problem is that today’s encrypted messages can be stored, and probably are. These will be able to be decrypted. So I agree with Simon that quantum computing isn’t necessarily a good thing (Letters, 15 March).
