Reprogram Verifone VX520 for Offline Transactions

I need an experienced developer to reprogram a Verifone VX520 POS device for offline transactions. The device currently runs on Verix OS and uses protocol 201.3 with a 6-digit release code.

Requirements:
- Experience with Verifone devices, particularly VX520
- Proficiency in Verix OS and protocol 201.3
- Ability to implement secure offline transaction processing

Ideal Skills:
- Background in payment systems and POS configuration
- Strong technical troubleshooting skills
- Knowledge of security protocols for offline transactions

Please provide relevant experience in your bid.