my 2c security tips: - i trust my browser and site owner version : text in clear - i barely trust site owners ( if a match is found they still have access th

my 2c security tips: - i trust my browser and site owner version : text in clear - i barely trust site owners ( if a match is found they still have access the fact that I've verified that number ) : hash each phone address hashed ie using bcrypt and using a composed salt ( ie : site address + email in the account + phone address ) so rainbow table will be impossible to use ( this because phone numbers are low entropy and even without rainbow table IMO are not that very secure ) than ask user for the hashed version in the text field ( also write a linux terminal style command that can be used to hash given salt and hashing , or redirect to a trusted hasher service online (multiple links can be provided ) ) both text fields can be provided to allow the user a choice