For actual randomised crypto based OTP you’d be looking at the Spark2 or the Apex. However, the examples you gave regarding unlocking a PC or apps, I wouldnt recommend either of those products.
From what Ive gathered you are looking for something with:
- Some storage
- Preferably High Frequency and NFC compliant/usable (so it can work with a phone)
These were the only 2 main points I found to describe the type of implant; not what it is going to be used for.
Many, if not all of the HF implants support these requirements. The NExT is the more popular choice as it combines HF and LF into one.
The HF side uses an NTAG216 which has 888 bytes of user write able storage, NFC Forum Type 2 compliant and supports NDEF messages. In other words, it has a decent amount of memory, it can be read/written from a phone and you can store URLs/phone numbers/email/address/etc.
To unlock a PC with an implant, you could use the KRB1 which reads the chip’s UID and types it as the password. This isnt a randomised nor crypto generated process but more of a static method. Of course your password would need to be the same as the chip’s UID for it to work.
Im not too sure what is meant by this and would like some additional elaboration if possible.
Both the xDF2 and NExT are glass encapsulated implants meaning they can be implanted using the supplied injectors; no need for scalpel/flex needle work.
The biggest difference is the chipsets they use.
The NExT is a dual frequency implant that combines an NTAG216 (HF) and a T5577 (LF) into one. This gives you some versatility in that you have an NFC compliant HF implant and a very versatile LF chipset that can emulate most LF cards.
The xDF2 uses a Mifare DESFire Ev2 chip which is more commonly used in access control systems from its impressive secure feature set. For an end user, it does boast a large memory size of 8KB, unique file system, NFC Forum Type 4 compliant along with may other features. Given it is commonly used in PACS, there is more of a challenge to configure the additional features which would be difficult to do solely with a phone.
Overall, a NExT sounds like it would fit your use case quite well. Its a very versatile implant and commonly bought as a first implant for those starting out. I know Im firmly in that statistic.