Invertibility Checker (mod n) for 2x2 matrix
Enter the 2×2 matrix
a
b
c
d
Modulus n
Entries can be any integers (negatives or larger than n are fine).
Check invertibility
Clear
Enter values and press
Check invertibility
.
Text → Numbers Converter
Enter text
Choose base
26 (letters only)
29 (letters + space + . + ?)
Convert
Clear
Enter text and select base to see numeric array.
Numbers → Text
Base
26 (letters only)
29 (letters + space + . + ?)
Comma-separated numbers (0 … base−1)
Convert to text
Clear
Enter numbers and choose a base.
Encryption (Hill 2×2)
Base
26 (letters only)
29 (letters + space + . + ?)
Key input type
Letters (4 chars)
Numbers (a,b,c,d)
Key forms [[a,b],[c,d]]. If you type letters: a→0 … z→25.
Message input type
Text
Numbers (comma-separated)
Encrypt
Clear
Enter key & message (text or numbers), pick a base, then Encrypt.
Decryption (Hill 2×2)
Base
26 (letters only)
29 (letters + space + . + ?)
Key input type
Letters (4 chars)
Numbers (a,b,c,d)
Key forms [[a,b],[c,d]]. Letters map a→0 … z→25.
Ciphertext input type
Text
Numbers (comma-separated)
Decrypt
Clear
Enter key & ciphertext (text or numbers), pick a base, then Decrypt.