What technique allows the replacement of data with random characters while preserving other traits such as string length?

The technique that allows the replacement of data with random characters while preserving other traits, such as string length, is randomization. Randomization works by effectively obfuscating the data, creating a new set of characters that does not reveal the original data while maintaining specific characteristics, such as the length of the string. This is particularly useful in contexts where data needs to be anonymized or protected without changing the structure required by the system that uses it.

Encryption, while it also alters the original data, is meant primarily for confidentiality and does not necessarily preserve the overall length and structure in the way randomization does. Encoding transforms data into a different format but aims for data integrity rather than obfuscation, and compression reduces data size without necessarily focusing on character replacement or string length preservation. Thus, randomization stands out as the technique specifically intended for this purpose.