TOTP 100% qb64 Yup - sorta LOL

[Jack]

I have only briefly scanned this thread but I gather that in order to implement the  Time-based One-Time Password you need some form of encryption, there's a public domain C library https://www.libtom.net/LibTomCrypt/

Ciphers Supported:

• AES (aka Rijndael)
  
• Anubis (with optional tweak as proposed by the developers)
  
• Blowfish
  
• CAST5
  
• Camellia
  
• DES, two-key 3DES, 3DES
  
• KASUMI
  
• Khazad
  
• Multi2
  
• Noekeon
  
• RC2
  
• RC5
  
• RC6
  
• SAFER (K64, SK64, K128, SK128)
  
• SAFER+
  
• SEED
  
• Skipjack
  
• Twofish
  
• XTEA
  

maybe you can use that library or borrow some code/ideas