---
title: "SFTP Documentation Information"
slug: "sftp-connection-security-requirements"
updated: 2024-03-12T16:30:19Z
published: 2024-03-12T16:30:19Z
canonical: "docs.interprose.com/sftp-connection-security-requirements"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.interprose.com/llms.txt
> Use this file to discover all available pages before exploring further.

# SFTP Connection Security Requirements

**Article details:**

**Access to the InterProse SFTP server must meet certain security requirements.**

Please consult with your technical resources to verify that the methods you or your clients are using to connect to an InterProse SFTP such as a SFTP client host like WinSCP or FileZilla server match one of those listed here.

If you experience SFTP challenges, please contact support.

### Key Exchange Algorithms

| `kex-strict-s-v00@openssh.com` |  | Unknown |
| --- | --- | --- |
| `diffie-hellman-group14-sha256` | Diffie-Hellman with 2048-bit Oakley Group 14 with SHA-256 hash[](https://tools.ietf.org/html/draft-ietf-curdle-ssh-modp-dh-sha2-01) Oakley Group 14 should be secure for now. | Secure |
| `diffie-hellman-group16-sha512` | Diffie-Hellman with 4096-bit MODP Group 16 with SHA-512 hash[](https://tools.ietf.org/html/draft-ietf-curdle-ssh-modp-dh-sha2-01) | Secure |
| `diffie-hellman-group18-sha512` | Diffie-Hellman with 8192-bit MODP Group 18 with SHA-512 hash[](https://tools.ietf.org/html/draft-ietf-curdle-ssh-modp-dh-sha2-01) | Secure |
| `diffie-hellman-group-exchange-sha256` | Diffie-Hellman with MODP Group Exchange with SHA-256 hash[](https://tools.ietf.org/html/rfc4419) | Secure |
| `curve25519-sha256` | Elliptic Curve Diffie-Hellman on Curve25519 with SHA-256 hash[](https://tools.ietf.org/html/draft-ietf-curdle-ssh-curves-00) | Secure |
| `curve25519-sha256@libssh.org` | Elliptic Curve Diffie-Hellman on Curve25519 with SHA-256 hash[](https://tools.ietf.org/html/draft-ietf-curdle-ssh-curves-00) | Secure |
| `ecdh-sha2-nistp256` | Elliptic Curve Diffie-Hellman on NIST P-256 curve with SHA-256 hash[](https://tools.ietf.org/html/rfc5656) [Possible NSA backdoor](https://safecurves.cr.yp.to/). | Secure |
| `ecdh-sha2-nistp384` | Elliptic Curve Diffie-Hellman on NIST P-384 curve with SHA-384 hash[](https://tools.ietf.org/html/rfc5656) [Possible NSA backdoor](https://safecurves.cr.yp.to/). | Secure |
| `ecdh-sha2-nistp521` | Elliptic Curve Diffie-Hellman on NIST P-521 curve with SHA-512 hash[](https://tools.ietf.org/html/rfc5656) [Possible NSA backdoor](https://safecurves.cr.yp.to/). | Secure |
| `diffie-hellman-group14-sha1` | Diffie-Hellman with 2048-bit Oakley Group 14 with SHA-1 hash[](https://tools.ietf.org/html/rfc4253) SHA-1 is becoming obsolete, consider using SHA-256 version. | Weak |

### Server Host Key Algorithms

| `ssh-ed25519` | Ed25519, an Edwards-curve Digital Signature Algorithm (EdDSA)[](https://tools.ietf.org/html/draft-bjh21-ssh-ed25519-02) | Secure |
| --- | --- | --- |
| `ecdsa-sha2-nistp256` | Elliptic Curve Digital Signature Algorithm (ECDSA) on NIST P-256 curve with SHA-256 hash[](https://tools.ietf.org/html/rfc5656) [Possible NSA backdoor](https://safecurves.cr.yp.to/). | Secure |
| `rsa-sha2-256` | RSA with SHA-256 hash[](https://tools.ietf.org/html/draft-ietf-curdle-rsa-sha2-02) | Secure |
| `rsa-sha2-512` | RSA with SHA-512 hash[](https://tools.ietf.org/html/draft-ietf-curdle-rsa-sha2-02) | Secure |
| `ssh-rsa` | RSA with SHA-1 hash[](https://tools.ietf.org/html/rfc4253) SHA-1 is becoming obsolete. | Weak |

### Encryption Algorithms

| `chacha20-poly1305@openssh.com` | 256-bit ChaCha20 with Poly1305 authenticator by OpenSSH[](https://tools.ietf.org/html/draft-josefsson-ssh-chacha20-poly1305-openssh-00) | Secure |
| --- | --- | --- |
| `aes256-gcm@openssh.com` | AES with 256-bit key in GCM mode by OpenSSH[](https://www.openssh.com/txt/release-6.2) | Secure |
| `aes128-gcm@openssh.com` | AES with 128-bit key in GCM mode by OpenSSH[](https://www.openssh.com/txt/release-6.2) | Secure |
| `aes256-ctr` | AES with 256-bit key in CTR mode[](https://tools.ietf.org/html/rfc4344) | Secure |
| `aes128-ctr` | AES with 128-bit key in CTR mode[](https://tools.ietf.org/html/rfc4344) | Secure |
| `aes256-cbc` | AES with 256-bit key in CBC mode[](https://tools.ietf.org/html/rfc4253) [A vulnerability exists in SSH messages that employ CBC mode that may allow an attacker to recover plaintext from a block of ciphertext.](https://www.kb.cert.org/vuls/id/958563) | Weak |
| `aes128-cbc` | AES with 128-bit key in CBC mode[](https://tools.ietf.org/html/rfc4253) [A vulnerability exists in SSH messages that employ CBC mode that may allow an attacker to recover plaintext from a block of ciphertext.](https://www.kb.cert.org/vuls/id/958563) | Weak |
| `3des-cbc` | TripleDES with 192-bit key (112-bit effective security) in CBC mode[](https://tools.ietf.org/html/rfc4253) 3DES is very inefficient. | Weak |

### MAC Algorithms

| `hmac-sha2-256-etm@openssh.com` | Hash-based MAC using SHA-256 (Encrypt-then-MAC) by OpenSSH | Secure |
| --- | --- | --- |
| `umac-128-etm@openssh.com` | 128-bit Universal Hashing MAC (Encrypt-then-MAC) by OpenSSH[](https://tools.ietf.org/html/draft-miller-secsh-umac-01) | Secure |
| `hmac-sha2-512-etm@openssh.com` | Hash-based MAC using SHA-512 (Encrypt-then-MAC) by OpenSSH | Secure |
| `hmac-sha2-256` | Hash-based MAC using SHA-256[](https://tools.ietf.org/html/rfc6668) | Secure |
| `umac-128@openssh.com` | 128-bit Universal Hashing MAC by OpenSSH[](https://tools.ietf.org/html/draft-miller-secsh-umac-01) | Secure |
| `hmac-sha2-512` | Hash-based MAC using SHA-512[](https://tools.ietf.org/html/rfc6668) | Secure |
| `hmac-sha1-etm@openssh.com` | Hash-based MAC using SHA-1 (Encrypt-then-MAC) by OpenSSH SHA-1 is becoming deprecated - consider replacing with SHA-256 or SHA-512. | Weak |
| `hmac-sha1` | Hash-based MAC using SHA-1[](https://tools.ietf.org/html/rfc4253) SHA-1 is becoming deprecated - consider replacing with SHA-256 or SHA-512. | Weak |

### Compression Algorithms

| `none` | No compression[](https://tools.ietf.org/html/rfc4253) | Unknown |
| --- | --- | --- |
| `zlib@openssh.com` | zlib compression by OpenSSH[](https://www.openssh.com/txt/draft-miller-secsh-compression-delayed-00.txt) | Unknown |

### Server Public Keys

#### rsa-sha2-512

| Key size: | 2048bit |
| --- | --- |
| MD5 Fingerprint: | `59:cb:c3:a9:78:81:61:a7:b7:e0:27:f7:b3:e4:f6:b4` |
| SHA-256 Fingerprint: | `iE4mfKOMNZVzInEWJGGBYo7JFsRipx+Tg+ZTQZTFVrc` |
| Public key: | ```plaintext ---- BEGIN SSH2 PUBLIC KEY ---- Comment: "Saved by Rebex SSH" AAAAB3NzaC1yc2EAAAADAQABAAABAQChQVvNQT17takDkGMZbNYxy8zEO4/BxlBe 2vweecnn7GHhE5uLvePOC79lJtdQCROFnSPPIk9hCOROZCgOxzZ/N17RWDKuwISh yl3EqJpKLVmQKqmADtPyx4I3sZA1aR/7Q4l1Pp5x+C1HY2y9zfklZiA38rOJQPlv tF9U6bSlLgke+QLCuUdJub/tlY2LJVpNLnp3QwOcyZXU1FL9cs3ZVkVJWoqZ+xZ/ X34hOwBzfGxFqkW3qFHyuPNWUkuD0EnnXYhH61RO4eRwsQLBfMwhDlQDRLxyX0lA YGsaG33gSpSZDtpGV8LBibYzzdXWAKpDoqf9PP0A3xzphAJogAPt ---- END SSH2 PUBLIC KEY ---- ``` |

#### rsa-sha2-256

| Key size: | 2048bit |
| --- | --- |
| MD5 Fingerprint: | `59:cb:c3:a9:78:81:61:a7:b7:e0:27:f7:b3:e4:f6:b4` |
| SHA-256 Fingerprint: | `iE4mfKOMNZVzInEWJGGBYo7JFsRipx+Tg+ZTQZTFVrc` |
| Public key: | ```plaintext ---- BEGIN SSH2 PUBLIC KEY ---- Comment: "Saved by Rebex SSH" AAAAB3NzaC1yc2EAAAADAQABAAABAQChQVvNQT17takDkGMZbNYxy8zEO4/BxlBe 2vweecnn7GHhE5uLvePOC79lJtdQCROFnSPPIk9hCOROZCgOxzZ/N17RWDKuwISh yl3EqJpKLVmQKqmADtPyx4I3sZA1aR/7Q4l1Pp5x+C1HY2y9zfklZiA38rOJQPlv tF9U6bSlLgke+QLCuUdJub/tlY2LJVpNLnp3QwOcyZXU1FL9cs3ZVkVJWoqZ+xZ/ X34hOwBzfGxFqkW3qFHyuPNWUkuD0EnnXYhH61RO4eRwsQLBfMwhDlQDRLxyX0lA YGsaG33gSpSZDtpGV8LBibYzzdXWAKpDoqf9PP0A3xzphAJogAPt ---- END SSH2 PUBLIC KEY ---- ``` |

#### ssh-rsa

| Key size: | 2048bit |
| --- | --- |
| MD5 Fingerprint: | `59:cb:c3:a9:78:81:61:a7:b7:e0:27:f7:b3:e4:f6:b4` |
| SHA-256 Fingerprint: | `iE4mfKOMNZVzInEWJGGBYo7JFsRipx+Tg+ZTQZTFVrc` |
| Public key: | ```plaintext ---- BEGIN SSH2 PUBLIC KEY ---- Comment: "Saved by Rebex SSH" AAAAB3NzaC1yc2EAAAADAQABAAABAQChQVvNQT17takDkGMZbNYxy8zEO4/BxlBe 2vweecnn7GHhE5uLvePOC79lJtdQCROFnSPPIk9hCOROZCgOxzZ/N17RWDKuwISh yl3EqJpKLVmQKqmADtPyx4I3sZA1aR/7Q4l1Pp5x+C1HY2y9zfklZiA38rOJQPlv tF9U6bSlLgke+QLCuUdJub/tlY2LJVpNLnp3QwOcyZXU1FL9cs3ZVkVJWoqZ+xZ/ X34hOwBzfGxFqkW3qFHyuPNWUkuD0EnnXYhH61RO4eRwsQLBfMwhDlQDRLxyX0lA YGsaG33gSpSZDtpGV8LBibYzzdXWAKpDoqf9PP0A3xzphAJogAPt ---- END SSH2 PUBLIC KEY ---- ``` |

#### ecdsa-sha2-nistp256

| Key size: | 256bit |
| --- | --- |
| MD5 Fingerprint: | `d1:19:d1:ae:da:a9:d6:20:fd:84:e8:ff:03:f6:d2:93` |
| SHA-256 Fingerprint: | `wn90sbJCc8b16PwdjHvYo018YPjdVJhaWsSIIjCZWD0` |
| Public key: | ```plaintext ---- BEGIN SSH2 PUBLIC KEY ---- Comment: "Saved by Rebex SSH" AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBJ4ZctHWN8Is i6yLzQQuUJDgFX6S3Ylf+Zo5DlTYsfkt0CcyfaOcZK+6akdKvD7/LPrWtA1olGVR eZyWAo/6ylY= ---- END SSH2 PUBLIC KEY ---- ``` |

#### ssh-ed25519

| Key size: | 256bit |
| --- | --- |
| MD5 Fingerprint: | `54:bd:f6:83:13:f1:58:70:eb:00:ad:e6:ff:b0:22:33` |
| SHA-256 Fingerprint: | `7p9pRhDwdHx+gQuiQPhqDSRNFAn+ED39ZW96qjON6OE` |
| Public key: | ```plaintext ---- BEGIN SSH2 PUBLIC KEY ---- Comment: "Saved by Rebex SSH" AAAAC3NzaC1lZDI1NTE5AAAAIAxs/8hJZYgK82K1ldk8nfAxUyDL7d4iO32ZlBDQ piCx ---- END SSH2 PUBLIC KEY ---- ``` |