Malicious SS7 activity and why SMS should never by used for 2FA

Mon Apr 19 14:01:06 UTC 2021

>
> These low-income people are not the targets of identity thieves, spear
> fishers, or data ransomers.
>

This is patently false. Low-income / disabled / minority / non-english
speakers are absolutely targets of scams like those, and in
significant numbers.

On Mon, Apr 19, 2021 at 9:33 AM Mel Beckman <mel at beckman.org> wrote:

> Tom,
>
> Well, yes, not everyone can afford all technology options. That’s life.
> One has to wonder how someone who needs to protect online accounts cannot
> afford a $30 hardware token (which can be shared across several accounts).
> These low-income people are not the targets of identity thieves, spear
> fishers, or data ransomers. Unlike you, I AM arguing against something: SMS
> as a 2FA token. In this case I don’t think we have ignored low-income
> users, for the same reason that home alarm security aren't ignoring
> low-income users who can’t afford their products. It’s certainly no reason
> to hobble security for the rest of us.
>
>  -mel
>
>
> On Apr 19, 2021, at 6:07 AM, Tom Beecher <beecher at beecher.cc> wrote:
>
> HW tokens are great, sure.
>
> Except there is a lot of overlap in the Venn diagram between those who
> still use feature phones and those that spending $30 on said hardware token
> is financially obtrusive. ( Not to mention that every hardware token I can
> remember looking at requires an app to set themselves up in the first
> place, and if this is for the people who can't install apps, that's an
> interesting circular dependency. )
>
> I'm not arguing for or against anything here honestly. I'm just pointing
> out that we ( as in the technical community we ) have a tendency to put
> forward solutions that completely ignore what might be reasonably feasible
> for those of lower income , or parts of the world not as technologically
> developed as we might be in ourselves, and we should try to shrink that gap
> whenever possible, not make it worse.
>
> On Mon, Apr 19, 2021 at 8:47 AM Mel Beckman <mel at beckman.org> wrote:
>
>> Then they can buy a hardware token. Using SMS is provably insecure, and
>> for people being spear-phished (a much more common occurrence now that so
>> much net worth data has been breached), a huge risk
>>
>>  -mel
>>
>> On Apr 19, 2021, at 5:44 AM, Tom Beecher <beecher at beecher.cc> wrote:
>>
>> 
>>
>>> As far as I know, authenticators on cell phone apps don’t require the
>>> Internet. For example, the Google Authenticator mobile app doesn't require
>>> any Internet or cellular connection
>>>
>>
>> Lots of people still use feature phones that are not capable of running
>> applications such as this.
>>
>> On Sun, Apr 18, 2021 at 9:05 AM Mel Beckman <mel at beckman.org> wrote:
>>
>>> As far as I know, authenticators on cell phone apps don’t require the
>>> Internet. For example, the Google Authenticator mobile app doesn't require
>>> any Internet or cellular connection. The authenticated system generates a
>>> secret key - a unique 16 or 32 character alphanumeric code. This key is
>>> scanned by GA or can be entered manually and as a result, both the
>>> authenticated system and GA know the same secret key, and can compute the
>>> time-based 2nd factor OTP just as hardware tokens do.
>>>
>>> There are two algorithms: HOTP and TOTP. The main difference is in OTP
>>> expiration time: with HOTP, the OTP is valid until it hasn’t been used;
>>> TOTP times out after some specified interval - usually 30 or 60 seconds.
>>> For TOTP, the system time must be synced, otherwise the generated OTPs will
>>> be wrong. But you can get accurate enough clock time without the Internet,
>>> either manually using some radio source such as WWV, or by GPS or cellular
>>> system synchronization.
>>>
>>>  -mel
>>>
>>> > On Apr 18, 2021, at 5:46 AM, Mark Tinka <mark at tinka.africa> wrote:
>>> >
>>> > 
>>> >
>>> >> On 4/18/21 05:18, Mel Beckman wrote:
>>> >>
>>> >> No, every SMS 2FA should be prohibited by regulatory certifications.
>>> The telcos had years to secure SMS. They did nothing. The plethora of
>>> well-secured commercial 2FA authentication tokens, many of them free,
>>> should be a mandatory replacement for 2FA in every security governance
>>> regime, such as PCI, financial account access, government web portals, etc.
>>> >
>>> > While I agree that SMS is insecure at the moment, I think there still
>>> needs to be a mechanism that does not rely on the presence of an Internet
>>> connection. One may not be able to have access to the Internet for a number
>>> of reasons (traveling, coverage, outage, device, money, e.t.c.), and a
>>> fallback needs to be available to authenticate.
>>> >
>>> > I know some companies have been pushing for voice authentication for
>>> their services through a phone call, in lieu of SMS or DTMF-based PIN's.
>>> >
>>> > We need something that works at the lowest common denominator as well,
>>> because as available as the Internet is worldwide, it's not yet at a level
>>> that one would consider "basic access".
>>> >
>>> > Mark.
>>>
>>
>
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