| crypto/rand | Package rand implements a cryptographically secure pseudorandom number generator. |
| crypto/subtle | Package subtle implements functions that are often useful in cryptographic code but require careful thought to use correctly. |
| encoding/base64 | Package base64 implements base64 encoding as specified by RFC 4648. |
| errors | Package errors implements functions to manipulate errors. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| golang.org/x/crypto/blowfish | Package blowfish implements Bruce Schneier's Blowfish encryption algorithm. |
| io | Package io provides basic interfaces to I/O primitives. |
| strconv | Package strconv implements conversions to and from string representations of basic data types. |