Is there a practical security difference between “OTP with letters” and “OTP with numbers”?
If, for example, I encrypt a letter message using Tabula Recta with a random letter key, I would get:
THISI SATES TXAAA - message MOSSK VFXNN EJRQW - OTP key FVAKS NFQRF XGRQW - cipher
Would such encryption be less secure when it comes to frequency analysis, compared to (let's say) Dirk Rijmenant's CT-46 OTP where the most frequent letters (
AEINOR) are associated with a single digit instead of two digits, like the rest of the less frequent letters in the alphabet?
THISI SATES TXAAA 83753 82390 82183 28290 83871 11000 - message 08733 64840 36236 58407 58482 94160 - OTP key 85020 28550 56957 70893 35499 27940 - cipher