The J-PAKE is a password-authenticated key exchange protocol that is included in the OpenSSL library and is currently in use. However, a future quantum computer utilising Shor’s algorithm for determining the discrete logarithm has posed a threat to the J-PAKE which its security relies on the difficulty of solving the Discrete Logarithm Problem. An algorithm similar to the J-PAKE is presented here. In contrast to the traditional J-PAKE, It uses floating-point numbers to generate a shared secret. The decimal part is used for the one-way function, transforming the protocol into a post-quantum key generation procedure. This is based on the fact that there is currently no quantum computer algorithm that can reverse engineer the one-way function. Performance is compared with the original J-PAKE. Theoretical analysis suggests that the proposed protocol is quantum-safe and offers reduced communication and computation cost as compared to the original J-PAKE.