Secure communications, hidden identifiers, secure internet and other advantages are promised by crypto SIM vendors, telling about various encryption options available around the world.
The first detailed analysis shows that there is no forced encryption, no protection against interception, no connection to alternate base station, no IMSI hiding, no location hiding.
Finally we have: number and voice spoofing. It should be noted that real voice spoofing exists and is available to an ordinary person, but it’s far from crypto SIM options and any other mobile solution, because the real voice is revealed by simple reversing, i.e. reverse deceleration, acceleration, tone decrease or increase. To change the voice irrevocably and keep it still human, you need a whole software package, with additional codecs, templates, as well as some knowledge (at least an understanding of what tracks, faders are). Each move of any slider will turn the voice into a rattle. There is only one conclusion – competence is needed.
So, what is a crypto SIM-card?
Ordinary SIM card + number substitution + voice substitution (very dubious).
And even if we are not taking into account the price and additional services, as soon as you turn on your phone, it automatically becomes a personal tracker, since IMEI does not change.
Such things as:
1. Lack of billing (direction finding or location)
2. Protection against interception (third-party base stations, wiretapping)
3. At least some decent channel encryption
All this is unachievable with SIM card and GSM in general. There is no secure GSM connection with active protocol from the 80s, what can we talk about here?
These threats (1-2-3) can only be bypassed manually:
(a) changing SIM cards and IMEI regularly
(b) not communicating via a GSM channel, i.e. no voice and sms, only internet, only hardcore