Solutions · Network operators

Every byte is airtime. Spend fewer on the handshake.

Cellular IoT reached around 4.5 billion connections at the end of 2025. On those links, security is paid for in bytes. AgilePQ measured 376 bytes to set up a SLiM session, against 2,728 to 3,478 for a TLS 1.2 handshake.

Talk to AgilePQ See the airtime

01Scale

Billions of connections. Each pays for its security in bytes.

Cellular IoT is forecast to grow from about 4.5 billion connections to 7.8 billion by 2031. LoRaWAN devices have reached 150 million, by the LoRa Alliance’s count.

4.5billion

cellular IoT connections at the end of 2025

7.8billion

forecast for 2031

150million

LoRaWAN devices deployed, by the LoRa Alliance’s count

Links AgilePQ has run SLiM over

NB-IoT
LTE-M
2G–4G
LoRaWAN
Sigfox
Satellite
BLE
Wi-Fi

02The handshake

Seven sessions in the bytes of one handshake.

AgilePQ measured a SLiM session setup at 376 bytes: 44 sent, 332 received. An OpenSSL TLS 1.2 handshake on a Raspberry Pi 3 took 2,728 bytes with a self-signed certificate and 3,478 with google.com’s.

One TLS 1.2 handshake: 2,728 to 3,478 bytes before the first reading moves.One SLiM session setup: 376 bytes.Seven SLiM setups fit in the bytes of the smaller handshake, nine in the larger.

Drawn to scale from AgilePQ’s measurements (April and July 2021). The counts are division: 2,728 ÷ 376 is 7.3, and 3,478 ÷ 376 is 9.3.

TLS 1.2 is the usual comparison, not the smallest. The IETF’s EDHOC, a handshake standard for small devices, sets up a session in 101 to 242 bytes. It does so with an elliptic-curve public-key exchange, the step SLiM does not have.

The same three sessions, as the bytes on the link

SLiM

376 B

TLS 1.2, self-signed

2,728 B

54 52 41 43 4B 45 52 3D 37 51 3B 4C 41 54 3D 34 30 2E 35 32 3B 54 52 41 43 4B 45 52 3D 37 51 3B 4C 41 54 3D 34 30 2E 35 32 3B 54 52 41 43 4B 45 52 3D 37 51 3B 4C 41 54 3D 34 30 2E 35 32 3B 54 52 41 43 4B 45 52 3D 37 51 3B 4C 41 54 3D 34 30 2E 35 32 3B 54 52 41 43 4B 45 52 3D 37 51 3B 4C 41 54 3D 34 30 2E 35 32 3B 54 52 41 43 4B 45 52 3D 37 51 3B 4C 41 54 3D 34 30 2E 35 32 3B 54 52 41 43 4B 45 52 3D 37 51 3B 4C 41 54 3D 34 30 2E 35 32 3B 54 52 41 43 4B 45 52 3D 37 51 3B 4C 41 54 3D 34 30 2E 35 32 3B 54 52 41 43 4B 45 52 3D 37 51 3B 4C 41 54 3D 34 30 2E 35 32 3B 54 52 41 43 4B 45 52 3D 37 51 3B 4C 41 54 3D 34 30 2E 35 32 3B 54 52 41 43 4B 45 52 3D 37 51 3B 4C 41 54 3D 34 30 2E 35 32 3B 54 52 41 43 4B 45 52 3D 37 51 3B 4C 41 54 3D 34 30 2E 35 32 3B 54 52 41 43 4B 45 52 3D 37 51 3B 4C 41 54 3D 34 30 2E 35 32 3B 54 52 41 43 4B 45 52 3D 37 51 3B 4C 41 54 3D 34 30 2E 35 32 3B 54 52 41 43 4B 45 52 3D 37 51 3B 4C 41 54 3D 34 30 2E 35 32 3B 54 52 41 43 4B 45 52 3D 37 51 3B 4C 41 54 3D 34 30 2E 35 32 3B 54 52 41 43 4B

TLS 1.2, google.com

3,478 B

No padding

SLiM does not pad data to 16- or 32-byte blocks.

2 to 10 bytes a packet

Per-packet overhead, including the integrity check, depending on mode.

Symmetric end to end

No RSA or elliptic-curve exchange to carry over the air, or to break.

Benchmarks are AgilePQ’s own engineering measurements, on the platforms named in the notes.

03The network is the target

The network itself is the target.

US and allied agencies say Salt Typhoon targeted telecommunications networks worldwide, alongside government, transportation and military networks. Volt Typhoon used end-of-life routers to pre-position inside US critical infrastructure.

An illustration: what an intruder inside the network can read.

Data encrypted at the device stays encrypted across every network it crosses, including one that has been compromised.

SLiM encrypts each packet at the device with a keystream that advances packet by packet, and adds an integrity check that exposes tampering.

The cellular link is now a way in. In December 2025 attackers reached a Polish heat and power plant’s control network through a private cellular network and shut down a steam turbine. CERT Polska called it the first such case it knew of.

04On the SIM

SLiM on the SIM. A proof of concept.

AgilePQ has built a proof of concept that delivers SLiM as a Java Card SIM applet. Operators who want to evaluate it can ask AgilePQ for a demonstration.

A SIM applet carries the encryption in the card rather than in the device firmware.

Ask for a demonstration

05Next step

Talk to AgilePQ about your network.

Tell AgilePQ the links, the devices and the traffic. SLiM reaches your network built into the devices that use it, and the SIM proof of concept is open to evaluation.

Talk to AgilePQ Schedule a demo

The other markets

01Device manufacturersBuild SLiM in once. Every device you ship carries it, into every market you sell to.02GovernmentSecrets with a long shelf life, sent from devices that stay in the field for years.04Utilities and critical infrastructureMeters, pumps and sensors that outlive the cryptography they shipped with.

All four markets · How SLiM works

06Sources

Sources and notes11 sources · 5 from AgilePQ’s own records

1Ericsson: “Total cellular IoT connections reached around 4.5 billion at the end of 2025”, forecast to reach 7.8 billion in 2031.Ericsson Mobility Report, IoT connections outlook (June 2026).Sourced
2AgilePQ measured 376 bytes to set up a SLiM session (44 sent, 332 received), against 2,728 bytes (self-signed certificate) and 3,478 bytes (google.com) for an OpenSSL TLS 1.2 handshake, on a Raspberry Pi 3.AgilePQ engineering benchmarks (April and July 2021).AgilePQ record
3LoRa Alliance: “LoRaWAN-connected devices have reached 150 million globally, growing at a rate of 25% CAGR.”LoRa Alliance press release (22 September 2026); the alliance’s own count.Sourced
4AgilePQ has run SLiM as a C library on microcontrollers and modules including Silicon Labs EFR32/EFM32, TI MSP430, CC1310, CC2640 and CC3220, Nordic, Espressif ESP32, Dialog DA14585, Raspberry Pi and Cisco 809/819, over BLE, Wi-Fi, LoRaWAN, Sigfox, NB-IoT, LTE-M, 2G–4G and satellite links.AgilePQ test platform list (2021).AgilePQ record
5IETF RFC 9528 (March 2024): EDHOC is “a very compact and lightweight authenticated Diffie-Hellman key exchange with ephemeral keys”; its example messages total 101 to 242 bytes. Diffie-Hellman over elliptic curves is a public-key method.IETF RFC 9528, Ephemeral Diffie-Hellman Over COSE (EDHOC).Sourced
6SLiM does not pad data to 16- or 32-byte blocks; per-packet overhead is 2 to 10 bytes depending on mode, including an integrity check. AgilePQ: SLiM “adds a 10-byte header per packet (which includes an integrity check)”.AgilePQ engineering documentation (2021); AgilePQ, SLiM byte savings (23 April 2021).AgilePQ record
7SLiM is symmetric end to end. A key server gives each device its own keys and issues session keys; the encryption changes with every packet. SLiM uses no RSA or elliptic-curve key exchange.AgilePQ, SLiM Overview v2.4 (April 2021) and SLiM Technical Overview v2.4.9 (January 2024).AgilePQ record
8US and allied agencies: Salt Typhoon targeted “telecommunications, government, transportation, lodging, and military infrastructure networks globally”.NSA, joint advisory AA25-239A (27 August 2025).Sourced
9CISA, NSA and FBI: Volt Typhoon is “pre-positioning themselves on IT networks to enable the disruption of OT functions across multiple critical infrastructure sectors”, with access maintained in some environments “for at least five years”, using “end-of-life SOHO routers”.CISA advisory AA24-038A (7 February 2024).Sourced
10CERT Polska: at a smaller combined heat and power plant “supplying heat to 50,000 residents”, “a steam turbine and the water treatment system used to produce process water were shut down”; the attack did not disrupt heat supplies to consumers. “To the best of our knowledge, the use of a private APN to gain access to the OT network was the first instance of this attack vector being observed in a real-world cyberattack.”CERT Polska, follow-up report on the December 2025 energy-sector incident (8 August 2026).Sourced
11AgilePQ has built a proof of concept delivering SLiM as a Java Card SIM applet.AgilePQ research documentation (2020).AgilePQ record