|Security of ICE-docs container|
From the article:
Softips: A Fistfull of Reasons for Compressing Data Using the 7z Archive Format
"7-Zip also supports encryption with the AES-256 algorithm. This algorithm uses a cipher key with length of 256 bits. To create the key, 7-Zip uses a derivation function based on an SHA-256 hash algorithm. A key derivation function produces a derived key from a text password defined by the user. To increase the cost of an exhaustive search for passwords, 7-Zip uses a big number of iterations to produce the cipher key from the text password."
The following table taken from the above article gives the time taken to crack a simple password created using only lower case letters. When using a larger character set, that includes all printable characters available on the keyboard, these numbers become greater. For such a set, 10 characters correspond to the 14 characters Password Length entry, which provide a high degree of security.