你可以用 transform 加密 ssn 结构数组中的字段：

// sample dataframe
df.show(false)
+----+-----+---------------------------+
|id  |name |kyc                        |
+----+-----+---------------------------+
|1001|smith|[[999, 12345, ss@mail.com]]|
+----+-----+---------------------------+

// sample schema
df.printSchema
// root
// |-- id: integer (nullable = false)
// |-- name: string (nullable = false)
// |-- kyc: array (nullable = false)
// |    |-- element: struct (containsNull = false)
// |    |    |-- pnno: integer (nullable = false)
// |    |    |-- ssn: integer (nullable = false)
// |    |    |-- email: string (nullable = false)

val df2 = df.withColumn(
    "kyc", 
    expr("""
        transform(kyc, 
            x -> struct(x.pnno pnno, sha2(string(x.ssn), 512) ssn, x.email email)
        )
    """)
)

df2.show(false)
+----+-----+------------------------------------------------------------------------------------------------------------------------------------------------------+
|id  |name |kyc                                                                                                                                                   |
+----+-----+------------------------------------------------------------------------------------------------------------------------------------------------------+
|1001|smith|[[999, 3627909a29c31381a071ec27f7c9ca97726182aed29a7ddd2e54353322cfb30abb9e3a6df2ac2c20fe23436311d678564d0c8d305930575f60e2d3d048184d79, ss@mail.com]]|
+----+-----+------------------------------------------------------------------------------------------------------------------------------------------------------+