Submitted by d3e4
https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Utils.sol#L136-L174 
https://github.com/code-423n4/2023-03-canto-identity/blob/077372297fc419ea7688ab62cc3fd4e8f4e24e66/canto-namespace-protocol/src/Utils.sol#L256-L261
Only a tiny fraction of all Zalgo distortions are accessible.
In characterToUnicodeBytes, for font class 7 (i.e. Zalgo), the _characterModifier determines the Zalgo distortion.
The distortion is pseudo-randomly calculated by using _characterModifier as a seed and iteratively passing it through iteratePRNG, each intermediate value being used to set, in turn, each component of the distortion.
This has the effect that the initial seed value generates a stream of values, equidistributed within their respective ranges.
A Zalgo tile is defined by a letter and a modification consisting of a combination of characters above, over and below the letter. The modification consists of a selection of 1 up to 7 characters from a set of 46 characters above the letter, 0 or 1 from 5 over the letter, and 1 to 7 from 47 below the letter. Thus there is a total of $(46^1 + 46^2 + ... + 46^7)*(5^0 + 5^1)*(47^1 + 47^2 + ... + 47^7) = 1.38e24$ different Zalgo modifications possible per letter.
However, iteratePRNG modulates its return value by 2038074743:
This means that after the first pass through iteratePRNG we only have 2038074743 different possibilities which will determine the rest of the distortion. The original _characterModifier is first used to set to uint256 numAbove = (_characterModifier % 7) + 1;. The remaining combinations are therefore 1.38e24 / 7 = 1.98e+23, which is vastly greater than 2038074743.
characterToUnicodeBytes can thus only return 7 * 2038074743 = 14266523201 different distortions per letter, which is only a tiny fraction of the actual number of distortions.
Note that it is similarly an issue that the range of _characterModifier is only 0..255, which issue is reportedly separately.
iteratePRNG must have a range of at least 1.98e+23 different values.
OpenCoreCH (Canto Identity) acknowledged
