As for me I'll just sing a message with my qora address using btc investment address. I think it's the most secure way.

1HyvPpAnmLpg5zLnR9k5dUDQfzi8ENWAdi
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Dear dev, this is my Qora address: Qoratest112233
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IHTCGxNob8fVyA0ZoCY5wt3Nb0IJCUJhV5dJ5QRU21lzUzjOYwFrps+2YfE+ol5Fk4LdATzEf35HtuXiezBByT0=